Media Bias by the Numbers_ Challenges and Opportunities in the Empirical Study of Partisan News

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高三英语统计学分析单选题60题及答案

高三英语统计学分析单选题60题及答案1.The average score of a class is calculated by adding all the scores and dividing by the number of students. This is an example of _____.A.meanB.medianC.modeD.range答案：A。

本题考查统计学基本概念。

A 选项mean（平均数）是通过将所有数据相加再除以数据个数得到的，符合题干描述。

B 选项median（（中位数）是将数据从小到大排列后位于中间位置的数。

C 选项mode（众数）是数据中出现次数最多的数。

D 选项range（极差）是数据中的最大值与最小值之差。

2.In a set of data, if there is a value that occurs most frequently, it is called the _____.A.meanB.medianC.modeD.range答案：C。

A 选项mean 是平均数。

B 选项median 是中位数。

C 选项mode 众数是出现次数最多的值，符合题意。

D 选项range 是极差。

3.The middle value in a sorted list of data is called the _____.A.meanB.medianC.modeD.range答案：B。

A 选项mean 是平均数。

B 选项median 中位数是排序后位于中间的数，符合题干描述。

C 选项mode 是众数。

D 选项range 是极差。

4.The difference between the highest and lowest values in a set of data is known as the _____.A.meanB.medianC.modeD.range答案：D。

meidia Bias and Reputation

280[Journal of Political Economy,2006,vol.114,no.2]᭧2006by The University of Chicago.All rights reserved.0022-3808/2006/11402-0004$10.00Media Bias and ReputationMatthew GentzkowUniversity of ChicagoJesse M.ShapiroUniversity of Chicago and National Bureau of Economic ResearchA Bayesian consumer who is uncertain about the quality of an infor-mation source will infer that the source is of higher quality when its reports conform to the consumer’s prior expectations.We use this fact to build a model of media bias in which ﬁrms slant their reports toward the prior beliefs of their customers in order to build a repu-tation for quality.Bias emerges in our model even though it can make all market participants worse off.The model predicts that bias will be less severe when consumers receive independent evidence on the true state of the world and that competition between independently owned news outlets can reduce bias.We present a variety of empirical evi-dence consistent with these predictions.We are extremely grateful to an anonymous referee for thorough and insightful com-ments on an earlier draft of this paper.We also thank Alberto Alesina,Attila Ambrus,Nigel Ashford,Chris Avery,Heski Bar-Isaac,Gary Becker,Tyler Cowen,Jonathan Feinstein,Jeremy Fox,Drew Fudenberg,Ed Glaeser,Jerry Green,James Heckman,Tom Hubbard,Steve Levitt,Larry Katz,Kevin M.Murphy,Roger Myerson,Canice Prendergast,Matthew Rabin,Andrei Shleifer,Lars Stole,Richard Thaler,Richard Zeckhauser,and seminar par-ticipants at Harvard University,the University of Chicago,the Institute for Humane Studies,and the University of British Columbia for helpful comments.We thank Christopher Avery,Judith Chevalier,Matthew Hale,Martin Kaplan,Bryan Boulier,and H.O.Stekler for generously providing access to their data.Karen Bernhardt,Fuhito Kojima,Jennifer Paniza,and Tina Yang provided excellent research assistance.Gentzkow acknowledges ﬁnancial assistance from the Social Science Research Council and the Centel Foundation/Robert P.Reuss Faculty Research Fund.Shapiro acknowledges ﬁnancial assistance from the In-stitute for Humane Studies,the Center for Basic Research in the Social Sciences,the Chiles Foundation,and the National Science Foundation.media bias and reputation281 I.IntroductionOn December2,2003,American troops fought a battle in the Iraqi city of Samarra.Fox News began its story on the event with the following paragraph:In one of the deadliest reportedﬁreﬁghts in Iraq since the fallof Saddam Hussein’s regime,US forces killed at least54Iraqisand captured eight others while fending off simultaneous con-voy ambushes Sunday in the northern city of Samarra.The New York Times article on the same event beganAmerican commanders vowed Monday that the killing of asmany as54insurgents in this central Iraqi town would serveas a lesson to thoseﬁghting the United States,but Iraqis dis-puted the death toll and said anger against America wouldonly rise.And the English-language Web site of the satellite network Al Jazeera ()beganThe US military has vowed to continue aggressive tactics aftersaying it killed54Iraqis following an ambush,but commandersadmitted they had no proof to back up their claims.The onlycorpses at Samarra’s hospital were those of civilians,includingtwo elderly Iranian visitors and a child.All the accounts are based on the same set of underlying facts.Yet by selective omission,choice of words,and varying credibility ascribed to the primary source,each conveys a radically different impression of what actually happened.The choice to slant information in this way is what we will mean in this paper by media bias.Such bias has been widely documented,both internationally and within the United States(Groseclose and Milyo2005).1Concern about bias has played a prominent role in many policy debates,ranging from public diplomacy in the Middle East(Satloff2003;Peterson et al.2003) to ownership regulation by the Federal Communications Commission (Cooper,Kimmelman,and Leanza2001).Moreover,survey evidence 1The differences between the slant of Arab and American news sources in covering the Middle East are documented at length by Ajami(2001).A sampling of recent works documenting bias in U.S.national media includes books by Alterman(2003),Coulter(2003),Franken(2003),and Goldberg(2003).Underhill and Pepper(2003)discuss ac-cusations of prejudicial reporting at the BBC.282journal of political economy revealing rising polarization and falling trust in the news media has prompted concerns about the market’s ability to deliver credible infor-mation to the public(Kohut2004).In this paper,we develop a new model of media bias.We start from a simple assumption:A mediaﬁrm wants to build a reputation as a provider of accurate information.If the quality of the information a givenﬁrm provides is difﬁcult to observe directly,consumer beliefs about quality will be based largely on observations of past reports.Firms will then have an incentive to shape these reports in whatever way will be most likely to improve their reputations and thus increase their future proﬁts by expanding the demand for their products.Ourﬁrst set of results shows thatﬁrms will tend to distort information to make it conform with consumers’prior beliefs.To see why,consider that a noisy or inaccurate signal is more likely to produce reports that contradict the truth.An agent who has a strong prior belief about the true state of the world will therefore expect inaccurate information sources to contradict that belief more often than accurate ones.Sup-pose,for example,that a newspaper reports that scientists have suc-cessfully produced cold fusion.If a consumer believes this to be highly unlikely a priori,she will rationally infer that the paper probably has poor information or exercised poor judgment in interpreting the avail-able evidence.A mediaﬁrm concerned about its reputation for accuracy will therefore be reluctant to report evidence at odds with consumers’priors,even if they believe the evidence to be true.The more priors favor a given position,the less likely theﬁrm becomes to print a story contradicting that position.Our second main result is that when consumers have access to a source that can provide ex post veriﬁcation of the true state of the world,ﬁrms’incentives to distort information are weakened.If aﬁrm misreports its signal so as to move closer to consumers’priors,it runs the risk that the truth will come out and its report will be falsiﬁed,damaging its reputation.As the likelihood of ex post feedback about the state of the world improves,the amount of bias occurring in equilibrium decreases. Our model therefore predicts less bias in contexts in which predictions are concrete and outcomes are immediately observable—weather fore-casting,sports outcomes,or stock returns,for example.It predicts more bias in coverage of a foreign war,discussion of the impact of alternative tax policies,or summary of scientiﬁc evidence about global warming, contexts in which outcomes are difﬁcult to observe and are often not realized until long after the report is made.The analysis of feedback foreshadows our third result:Competition in the news market can lead to lower bias.Aﬁrm competing with another news outlet runs the risk that,if it distorts its signal,the competitor’s report will expose the inaccuracy and thus reduce consumers’assess-media bias and reputation283 ments of the distortingﬁrm’s quality.We also show that if allﬁrms in a market are jointly owned,bias can remain unchanged even as the number ofﬁrms gets large.At the end of the paper,we present empirical evidence on the de-terminants of bias.We review a range of existing evidence suggesting that feedback can limit bias and that in high-feedback settings,such as weather reporting,bias tends to be relatively minor.We also highlight the fact that local sports columnists do not excessively favor their local teams in forecasting game outcomes,which is consistent with an im-portant role for rapid feedback in limiting the incentive to slant.Finally, we discuss anecdotal evidence suggesting that mediaﬁrms in more com-petitive markets have stronger incentives to reveal important informa-tion and show quantitatively that television news reports leading up to the2000election were more equitable in their treatment of Bush and Gore in more competitive markets.Formally,our work is most closely related to the literature on“herding on the priors,”which considers the way agents’incentives to act on or reveal information depend on the prior beliefs of those who will ulti-mately determine their rewards.In this vein,Brandenburger and Polak (1996)show that aﬁrm manager concerned about hisﬁrm’s current stock price may choose the action favored by shareholders’priors even when he has private information showing that this is inefﬁcient.The manager’s desire to maximize current stock prices plays a role similar to that of the reputational incentives in our framework:it gives the decision maker an incentive to slant its action toward the prior beliefs of another agent.Prendergast(1993)shows that similar concerns will lead a worker to skew her reports to match the data that her manager has received,again leading valuable information to be lost in equilib-rium.2In contrast to much of this literature,however,the reputational concerns we model provide an additional incentive for honesty,which in turn guarantees the presence of an informative equilibrium.In this sense,our model is also related to work on reputational effects in sender-receiver games(see,e.g.,Efﬁnger and Polborn2001;Morris2001;Avery and Meyer2003;Olszewski2004;Ottaviani and Sørensen2006,forth-coming).We deviate from these papers in highlighting the importance of the receiver’s prior beliefs for the equilibrium reporting strategy and in showing the effects of ex post revelation on equilibrium reporting.3 Our framework is also related to political scientists’models of“pan-dering”to voters(Canes-Wrone,Herron,and Shotts2001). Topically,our work is related to the growing body of economic re-2See also Heidhues and Lagerlo¨f(2003)for an application to political competition. 3See Ely,Fudenberg,and Levine(2002)and Ely and Va¨lima¨ki(2003)for other models in which reputational concerns lead to distortions in equilibrium.284journal of political economy search on media bias.Existing economic models of bias all take as given that some agents in the economy—consumers(Mullainathan and Shlei-fer2005),reporters(Baron2004),or governments(Besley and Prat 2004)—prefer news suppliers to distort the information they provide.4In contrast,our model shows that bias can arise even when consumers of news care only about learning the truth,sellers of news care only about maximizing proﬁts,and eliminating bias could make all agents in the economy better off.While we do not deny that some agents may prefer the news media to distort their reports,ourﬁndings suggest that caution is warranted in interpreting media slant as evidence for such tastes. Additionally,our framework generates novel,testable predictions that distinguish it from these existing theories.Most notably,our prediction that increased competition lowers the incentive to bias reports toward consumer priors contrasts sharply with that of Mullainathan and Shleifer (2005),who argue that increased competition will tighten the connection between priors and reports.In Section II,we discuss the role of reputational incentives in media markets.In Section III,we present the model for a simple monopoly case and show that equilibrium bias is correlated with consumer priors and decreasing in the amount of ex post feedback.In Section IV,we extend the model to allow for multipleﬁrms and develop the intuition that competition can reduce bias by increasing the likelihood that er-roneous reports are exposed.In Section V,we extend the model to allow consumers with heterogeneous prior beliefs to coexist in the same mar-ket.We show that it is possible to have segmented equilibria in which eachﬁrm provides information to only one type of consumer and slants its reports accordingly,and that the key comparative statics remain valid in this setting.Section VI presents empirical evidence supporting our keyﬁndings,and Section VII presents conclusions.II.Credibility,Quality,and Bias in the MediaIn this section,we present evidence supporting two key building blocks of our model:Mediaﬁrms try to build a reputation for truthful re-porting,and consumers’assessments of the quality of news sources de-pend on prior beliefs.We also present evidence conﬁrming the intuition suggested in theﬁrst paragraph of Section I thatﬁrms’reporting strat-egies are highly related to the prior beliefs of their consumers.4An earlier version of Mullainathan and Shleifer’s(2002)paper does not assume that consumers have a taste for conﬁrmatory information but generates similar behavior through a mechanism in which consumers think categorically.media bias and reputation285 A.The Importance of Reputation in Media MarketsAt the heart of our model will be mediaﬁrms’desire to maintain a reputation for accuracy in reporting.The high costsﬁrms are willing to incur to gather information provide strong evidence of such an in-centive,5as does the response of mediaﬁrms whose reports are revealed to have been inaccurate.For example,on September8,2004,CBS News anchor Dan Rather reported the emergence of new evidence indicating that President Bush’s family had pulled strings in order to get him into the Texas Air National Guard and avoid his having to serve in Vietnam. When later information indicated that the documents on which the report was based may have been fabricated,both Rather and Andrew Heyward,president of CBS,issued apologies emphasizing the impor-tance of a reputation for truth telling in journalism.Heyward wrote that “nothing is more important to[CBS]than our credibility and keeping faith with the millions of people who count on us for fair,accurate, reliable,and independent reporting.We will continue to work tirelessly to be worthy of that trust”(Heyward2004).Rather’s statement echoed Heyward’s,explaining that“nothing is more important to[CBS]than people’s trust in our ability and our commitment to report fairly and truthfully”(Rather2004).Similarly,the exposure of Jayson Blair’s fraudulent reporting at the New York Times prompted the resignation of top-ranking editors Howell Raines and Gerald M.Boyd.Former Tupperware chief executive Warren L.Batts remarked,“They,of course,had to resign....Any company has to sell the credibility of its product,but a media company has noth-ing else to sell”(Kirkpatrick and Fabrikant2003,B9).6B.The Inﬂuence of Priors on Quality AssessmentsOur model will draw on a general property of Bayesian updating about source quality,namely,that a source is judged to be of higher quality when its reports are more consistent with the agent’s prior beliefs.7A large body of psychological research documents a strong connection 5To take one example,Andrew Lack,president of NBC News,estimated at the beginning of the war in Afghanistan that covering it would cost each network approximately$1million per week—10percent of their total weekly expenditures(Auletta2001).One would not expect to see this level of expense if consumers were not signiﬁcantly concerned with the factual content of news.6An investigation by the Times discovered that Blair had“fabricated comments,”“con-cocted scenes,”and“selected details from photographs to create the impression he had been somewhere or seen someone,when he had not”(Barry et al.2003,1).New York Times publisher Arthur Sulzberger Jr.called Blair’s deceptions“an abrogation of the trust between the newspaper and its readers”(1).7Gentzkow and Shapiro(2005b)provide a proof of this property under fairly general conditions.See also Prendergast(1993)and Brandenburger and Polak(1996).286journal of political economyFig.1.—Political views and assessments of news media believability.Data come from the Pew Research Center for the People and the Press’s2002News Media Believability Survey. Exact wording for a survey question on respondent political views:“In general,would you describe your political views as very conservative,conservative,moderate,liberal,or very liberal?”Exact wording for a survey question on media believability:“Now,I’m going to read a list.Please rate how much you think you can BELIEVE each organization I name on a scale of4to1.On this four point scale,‘4’means you can believe all or most of what the organization says.‘1’means you believe almost nothing of what they say.How would you rate the believability of{the Fox News CABLE Channel/National Public Radio} on this scale of4to1?”between subjects’prior views and their assessments of information sources.In perhaps the best-known paper on this subject,Lord,Ross, and Lepper(1979)show that experimental subjects evaluating studies of the deterrence effect of the death penalty rate studies supporting their prior beliefs as both more“convincing”and“better done.”8This basicﬁnding is replicated and expanded by Lord,Lepper,and Preston (1984),Miller et al.(1993),and Munro and Ditto(1997).Along the same lines,Koehler(1993)shows that scientists rate experiments as higher-quality when the experimental results conform to the scientists’belief about a controversial issue.Evidence on consumer assessments of media quality in the real world shows a similar pattern.To take one example,ﬁgure1shows that in a recent survey,nearly30percent of respondents who described them-selves as“conservative”indicated that they thought they could believe 8This paper is often cited as evidence that consumers have conﬁrmatory bias,i.e.,a taste for information that conﬁrms their prior beliefs.We simply note that the evidence on evaluating the quality of information sources is equally consistent with a Bayesian model.media bias and reputation287 all or most of what the Fox Cable News Network says.In contrast,less than15percent of self-described liberals said that they could believe all or most of what the network reports.Ratings of National Public Radio show the opposite pattern:more than35percent of liberals believe all or most of what NPR says,as opposed to less than20percent of con-servatives.9Taken together,these pieces of evidence strongly suggest that prior beliefs inﬂuence consumers’judgments of quality in the way a Bayesian model would predict.C.The Inﬂuence of Consumer Priors on Media ReportsA large body of anecdotal evidence suggests a connection between con-sumers’prior beliefs and mediaﬁrms’slant.Consider,for example, Ames’s(1938,77)description of the problem faced by southern news-paper editors in their coverage of lynchings:“As individuals,they are unanimously opposed to mob violence but,as editors who are caught in the general atmosphere of a given trade territory,they do not reﬂect their own ideas but those of the people upon whose goodwill their papers depend for revenue.”The result of this pressure was that south-ern editorials in the period almost universally condoned lynchings.A more recent example is the reported difference in coverage of the war in Iraq between works and Arabic-language news channels such as Al Jazeera.As Lt.Josh Rushing,an American press ofﬁcer,ex-plains in the documentary Control Room,“It beneﬁts Al Jazeera to play to Arab nationalism because that’s their audience,just like Fox plays to American patriotism for the exact same reason”(Turan2004,E6). Even within a givenﬁrm,slant can vary depending on the audience. For example,CNN’s domestic cable channel broadcasts quite different content from CNN International,which is broadcast worldwide.Chris Cramer,president of CNN International,writes that its audience“ex-pects us to have a non-U.S.viewpoint.”The difference is also illustrated by coverage in the aftermath of September11:the domestic channel prominently displayed an Americanﬂag during its broadcasts whereas the international broadcasts quickly dropped theﬂag(Kempner2001, 1G).We now turn to more systematic evidence.Newspaper endorsements of presidential candidates display a pattern of conformity to local po-9Other evidence comes from Gallup Organization(2002).Respondents in nine Islamic countries were asked to report whether each of the followingﬁve descriptions applies toCNN:has comprehensive news coverage;has good analyses;is always on the site of events; has daring,unedited news;and has unique access to information.In Gentzkow and Shapiro (2005b),we show that an index of these quality assessments is strongly correlated with respondents’reported favorability toward the United States.To deal with the possibility of reverse causality,we also construct a proxy for favorability based on respondents’re-ported religiosity and show that this also has a strong correlation with quality assessments.288journal of political economyFig.2.—Newspaper endorsements and ideology across U.S.states in the2000election. Data on voting behavior are taken from the Federal Election Commission(http://www /elections.html).Percent for Bush reﬂects percentage of the two-party vote.Data on state per capita income come from USA Counties1998CD-ROM.Data on newspaper endorsements come from Bush()and Gore(http://www )ofﬁcial campaign sites;data posted at / Political.htm#Endorsements.Percent for Bush reﬂects percentage among papers endors-ing either Bush or Gore.litical opinion.Asﬁgure2shows,in the2000U.S.presidential election, Bush’s share of the two-party vote was considerably lower in richer states (Glaeser,Ponzetto,and Shapiro2005).Bush received almost60percent of the two-party vote among states in the lowest income quartile,as against just over40percent in the states in the highest quartile.As the ﬁgure illustrates,newspaper endorsements displayed a similar pattern, with almost90percent endorsing Bush in the bottom quartile and less than55percent in the top quartile.Although this graph is by no means conclusive,it certainly suggests a signiﬁcant connection between con-sumer beliefs and media slant.Existing work in political science also suggests a correlation between the editorial position of newspapers and the views of their readers.For example,Dalton,Beck,and Huckfeldt(1998)show survey evidence from the1992presidential election suggesting that the editorial stance of local newspapers is correlated with local perceptions of candidates. Erikson(1976)documents a similar relationship using aggregate data on voting patterns in the1960s.In Gunther’s(1992)analysis of national survey data,heﬁnds that only2percent of respondents had politicalmedia bias and reputation 289views categorized as “very distant”from those of their primary newspaper.III.Media Bias in a MonopolyIn this section we present a simple model in which a single media ﬁrm reports to homogeneous consumers.There is a binary state of the world,,and a large population of consumers who must each choose S ෈{L ,R }a binary action ,which gives a payoff of one if and a A ෈{L ,R }A p S payoff of zero otherwise.10We assume that consumers and the ﬁrm place prior probability v and v F ,respectively,on the true state being R .11At the beginning of the game,the ﬁrm receives a signal about s ෈{l ,r }the true state,whose distribution depends on the ﬁrm’s quality.With probability l ,the ﬁrm is “high-quality”and has a signal that perfectly reveals the true state.With probability ,the ﬁrm is “normal”and 1Ϫl has an imperfect but informative signal distributed according toPr (l d L )p Pr (r d R )p p ,where .We assume that the ﬁrm knows its own quality with1p ෈(,1)2certainty.We also assume that and .These1F v ෈[,p )v ෈(1Ϫp ,p )2restrictions ensure that the ﬁrm’s best guess as to the true state will depend on its signal and also that its signal will be valuable to con-sumers.12The assumption that is made without loss of generality 1v ≥2and serves to limit the set of cases we need to consider.After seeing its signal,the ﬁrm publishes a report .Normal ˆˆˆs ෈{l ,r}ﬁrms are free to report either or ,and we denote a normal ﬁrm’s ˆˆl rstrategy conditional on its signal by .Without loss of ˆˆj (s )p Pr (s d s )s generality,we will restrict attention to strategies with (cases ˆˆj (r)≥j (r )r l 10We follow much of the previous literature in modeling the information provided by media ﬁrms as an informative signal about some unknown state of the world,and assuming that consumers value this information because they face some decision whose payoffs are connected with the true state.This could represent actual decisions that depend on the news,either with large instrumental consequences (whether to join a terrorist group opposing the United States)or with minor consequences (what position to support in an argument with friends).It could also represent consumers who value information intrin-sically as in Grant,Kajii,and Polak (1998).11Although we will allow for the possibility that ,the choice to specify ﬁrm and F v p v consumer beliefs separately rather than assuming a common prior does affect the results slightly because it means that the comparative statics we present on v will hold the ﬁrm prior constant.As we point out below,however,the comparative statics would only be strengthened if we moved ﬁrm and consumer priors together.12In the case in which ,the ﬁrm’s best guess is that the true state is R regardless F p !v of its signal.We would want to deﬁne “bias”in this case to be the probability that the ﬁrm’s report deviates from its best guess of the true state (the proper deﬁnition with respect to welfare).Bias would therefore involve the ﬁrm’s reporting “too often”ˆl rather than too often as in the case we will analyze.However,the key comparative ˆr statics,that ﬁrm reports are correlated with consumer priors and that bias decreases with feedback,would remain unchanged.290journal of political economyin which this does not hold are equivalent to a relabeling of and ).ˆˆl rWe assume that high-quality ﬁrms always report their signal (and thus the true state)honestly.13The most straightforward interpretation of these assumptions is that the normal type has the freedom to lie.But note that our formulation can also accommodate subtler forms of bias such as “spin.”In the ex-ample discussed at the beginning of the paper,for example,we could think of two possible reporting strategies as “emphasize the fact that American troops were defending themselves”or “emphasize the fact that American troops killed a large number of Iraqis.”Replacing the option to report either or with this choice of emphasis would change ˆˆl rnothing about the formal structure of the game.In this reformulation,a news ﬁrm observes real-world events and then chooses what to em-phasize in its report.As long as high-quality ﬁrms emphasize civilian casualties more often when civilian casualties were actually high,this case will ﬁt naturally into our model.This observation is related to a common and fairly general feature of economic models of communi-cation,namely,that language has meaning only in equilibrium (Craw-ford and Sobel 1982).14Consumers choose whether or not to purchase the ﬁrm’s product and thus learn the value of .Rather than specify the pricing and proﬁt ˆsstructure in detail,we make two reduced-form assumptions:(i)all con-sumers purchase the product in equilibrium,and (ii)a change in the distribution of (conditional on the true state)that increases con-ˆssumers’willingness to pay for the ﬁrm’s report does not reduce con-sumer welfare and strictly increases ﬁrm proﬁts.These assumptions would hold,for example,in a model in which the ﬁrm sets a monopoly price and extracts all the consumer surplus.15After making the purchase decision and possibly learning ,each ˆsconsumer chooses an action A .Note that if consumers received utility from this action immediately,they would also know the true state.Since we wish to model feedback about the truth explicitly,we assume that13Allowing both types to have discretion would complicate the exposition and lead the model to have multiple equilibria in general.As we show in Gentzkow and Shapiro (2005b ),however,the equilibrium we analyze in which high types report truthfully is in fact the unique equilibrium of the more general model under an intuitive stability criterion.14Although the fact that the model is invariant to relabeling the reporting strategies is trivial,the comparative statics are also robust to more substantive changes in the way we model the technology of reporting.In Gentzkow and Shapiro (2005b ),we extend the model to allow for a continuous underlying signal,which approximates the case in which ﬁrms receive several signals each period and choose which to print and which to omit.We show that all our key results remain valid in this alternative speciﬁcation.15Alternatively,we could relax assumption i and allow the number of consumers who buy the ﬁrm’s product to depend on the expected value of the information in the ﬁrm’s report.A ﬁrm that set a zero price but extracted revenues from advertising would then be better off the more useful its reports were expected to be.。

24年6月四级试卷

24年6月四级试卷一、写作（15%）题目： The Importance of Lifelong Learning。

要求：1. 阐述终身学习的重要性。

2. 给出一些实现终身学习的途径。

3. 字数不少于120字，不多于180字。

二、听力理解（35%）Section A.Directions: In this section, you will hear three news reports. At the end of each news report, you will hear two or three questions. Both the news report and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A), B), C) and D).News Report 1.1. A) A new technology for solar energy storage.B) A major breakthrough in battery research.C) The development of a new type of electric vehicle.D) The discovery of a new energy source.Question 1: What is the news mainly about?Question 2: What is the potential impact of this discovery according to the report?News Report 2.2. A) A famous artist's new exhibition.B) The restoration of an ancient painting.C) A controversy over a modern art piece.D) The discovery of a long - lost painting.Question 1: What is the news item mainly about?Question 2: What are the different opinions mentioned in the report regarding this matter?News Report 3.3. A) A new policy on environmental protection.B) The effects of climate change on wildlife.C) A project to save endangered species.D) The discovery of a new species in the rainforest.Question 1: What is the main topic of the news report?Question 2: What measures are being taken in the project mentioned?Section B.Directions: In this section, you will hear two long conversations. At the end of each conversation, you will hear four questions. Both the conversation and the questions will be spoken only once. After you hear aquestion, you must choose the best answer from the four choices marked A), B), C) and D).Conversation 1.1. A) Discussing a study plan.B) Talking about a recent trip.C) Planning a party.D) Sharing reading experiences.Question 1: What are the two speakers mainly doing?Question 2: What does the man suggest about the activity?Question 3: How does the woman respond to the man's suggestion?Question 4: What will they probably do next?Conversation 2.2. A) Looking for a new apartment.B) Complaining about the neighbors.C) Discussing apartment decoration.D) Talking about rent prices.Question 1: What is the main topic of the conversation?Question 2: What problems does the woman mention about her current apartment?Question 3: What does the man suggest the woman do?Question 4: How does the woman feel about the man's suggestion?Section C.Directions: In this section, you will hear three passages. At the end of each passage, you will hear three questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A), B), C) and D).Passage 1.1. A) The history of coffee.B) The benefits of drinking coffee.C) Different ways of making coffee.D) Coffee culture around the world.Question 1: What is the passage mainly about?Question 2: Which of the following is mentioned as a benefit of coffee in the passage?Question 3: How is coffee consumed in some European countries according to the passage?Passage 2.2. A) The development of modern transportation.B) The impact of transportation on the environment.C) New trends in urban transportation.D) The future of self - driving cars.Question 1: What is the general topic of the passage?Question 2: What negative effect of transportation is emphasized in the passage?Question 3: What is said about self - driving cars in the passage?Passage 3.3. A) The importance of time management.B) Tips for effective study.C) How to overcome procrastination.D) The relationship between stress and study.Question 1: What is the main idea of the passage?Question 2: Which tip for study is mentioned in the passage?Question 3: How does the passage suggest dealing with stress related to study?三、阅读理解（35%）Section A.Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices. Each choice in the word bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2. You may not use any of the words in the word bank more than once.The Internet has become an _(1)_ part of our daily lives. It has changed the way we communicate, work, and learn. With just a few clicks, we can access a vast amount of information from all over the world. However, the Internet also brings some challenges. One of the major problems is the spread of false information. Some people may _(2)_ false news or rumors on the Internet, which can cause confusion and harm. Another issue is privacy. When we use the Internet, our personal information may be at risk. Hackers may try to steal our data, such as our passwords and credit card numbers.To address these problems, we need to be more _(3)_ when using the Internet. We should verify the sources of information before believing it. Also, we should take measures to protect our privacy, such as using strong passwords and avoiding sharing too much personal information online.Word Bank:A) essential.B) post.C) cautious.D) additional.E) limited.F) ignore.G) create.H) various.I) important.J) spread.Section B.Directions: In this section, you will read a passage followed by several questions. For each question, there are four choices marked A), B), C) and D). You should decide on the best choice and mark the corresponding letter on Answer Sheet 2.The concept of "smart cities" has been gaining popularity in recent years. A smart city is a city that uses technology to improve the quality of life for its residents. It involves the integration of various technologies such as the Internet of Things (IoT), big data, and artificial intelligence. In a smart city, sensors are installed throughout the city to collect data on different aspects such as traffic, air quality, and energy consumption. This data is then analyzed to make better decisions. For example, traffic lights can be adjusted based on real - time traffic flow, reducing congestion. Smart cities also aim to provide better services to their residents. For instance, citizens can use mobile apps to accesspublic services such as paying bills and reporting problems.1. What is the main idea of the passage?A) The definition and features of smart cities.B) The importance of technology in modern cities.C) The problems faced by cities in the digital age.D) The development of the Internet of Things in cities.2. According to the passage, how is data used in smart cities?A) To install more sensors.B) To develop new technologies.C) To make better decisions.D) To increase energy consumption.3. What can citizens do in a smart city according to the passage?A) They can control traffic lights.B) They can develop mobile apps.C) They can access public services via mobile apps.D) They can analyze big data.Section C.Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A), B), C) and D). You should decide on the best choice and mark the corresponding letter on your answer sheet.Passage 1.Reading books has always been a popular pastime. It not only enriches our knowledge but also broadens our horizons. There are different types of books, such as fiction, non - fiction, biographies, and self - help books. Fiction books can take us to different worlds and let us experiencedifferent emotions. Non - fiction books provide us with factual information on various topics. Biographies give us insights into the lives of great people. Self - help books offer advice on how to improve ourselves. However, in the digital age, the way we read books has changed. E - books have become increasingly popular. They are convenient as we can carry a whole library on a single device. But some people still prefer traditionalprinted books. They enjoy the feel of the paper and the smell of the ink.1. What is the passage mainly about?A) The benefits of reading different types of books.B) The popularity of e - books in the digital age.C) The comparison between e - books and printed books.D) The importance of reading in our lives.2. Which of the following is not mentioned as a type of book in the passage?A) Mystery books.B) Fiction books.C) Biographies.D) Self - help books.3. Why do some people prefer printed books according to the passage?A) Because they are cheaper.B) Because they are more convenient.C) Because they like the feel of paper and the smell of ink.D) Because they can carry more books.Passage 2.The rise of social media has had a significant impact on our communication. It has made it easier for people to connect with each other across the globe. Social media platforms such as Facebook, Twitter, and Instagram allow users to share their thoughts, photos, and videos. However,social media also has its downsides. One of the problems is the spread of false information. People may share untrue stories without verifying them. Another issue is cyberbullying. Some users may use social media to harass or bully others. To address these problems, social media companies are taking measures. For example, they are using algorithms to detect and remove false information. They are also implementing policies to prevent cyberbullying.1. What is the main topic of the passage?A) The positive effects of social media.B) The negative effects of social media and solutions.C) The development of social media platforms.D) The comparison between different social media platforms.2. Which of the following is a problem associated with social media according to the passage?A) The high cost of using social media.B) The lack of user privacy.C) The spread of false information.D) The slow speed of sharing content.3. How are social media companies dealing with the problems?A) By increasing user fees.B) By using algorithms and implementing policies.C) By reducing the number of users.D) By changing the design of the platforms.四、翻译（15%）题目：中国的城市化（urbanization）将会充分释放潜在内需（domestic demand）。

成人高考英语试卷加答案

Part I Listening Comprehension (25 points)Section A (5 points)In this section, you will hear five short conversations. At the end of each conversation, a question will be asked about what was said. Both the conversation and the question will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A), B), C) and D), and decide which is the best answer. Then mark the corresponding letter on Answer Sheet 2 with a single line through the centre.1. A) He doesn't have enough money.B) He doesn't need the book.C) He doesn't want to borrow the book.D) He can't find the book.2. A) The woman doesn't like coffee.B) The woman prefers tea.C) The woman doesn't drink tea.D) The woman has a bad habit.3. A) They are planning a vacation.B) They are discussing the weather.C) They are talking about a movie.D) They are discussing their work.4. A) She will go to the library.B) She will wait for the man.C) She will call the man.D) She will help the man.5. A) He doesn't like sports.B) He is not good at sports.C) He doesn't have time for sports.D) He prefers to watch sports.Section B (10 points)In this section, you will hear a passage three times. When the passageis read for the first time, you should listen carefully for general ideas. When the passage is read for the second time, you are required to fill in the blanks with the exact words you have just heard. Finally, when the passage is read for the third time, you should check what you have written.The Internet has become an essential part of our lives. It has revolutionized the way we communicate, work, and access information. (6) _ , it has also brought about both benefits and challenges.One of the major benefits of the Internet is the ease of communication. We can now connect with people from all over the world in an instant. (7) _ , we can easily share our thoughts, ideas, and experiences through social media platforms.However, along with these benefits come certain challenges. One of the most significant challenges is the issue of privacy. With the vast amount of personal information available online, there is a risk of identity theft and other forms of cybercrime. (8) _ , the Internet can also be a source of misinformation and fake news, which can be harmfulto individuals and society as a whole.Another challenge is the impact of the Internet on our social interactions. While it allows us to connect with others, it can alsolead to social isolation. Many people spend a significant amount of time online, which can reduce face-to-face interactions and lead to a decrease in social skills.Despite these challenges, the Internet remains a powerful tool that can be used for good. It is up to us to use it responsibly and make the most of its benefits while mitigating its risks.Part II Structure and Vocabulary (30 points)Section A (15 points)There are 15 incomplete sentences in this section. For each sentence there are four choices marked A), B), C) and D). Choose the one that best completes the sentence. Then mark the corresponding letter on Answer Sheet 2 with a single line through the centre.1. She has been working on her project for weeks, and she is almost______ it.A) finishedB) finishingC) finishD) to finish2. It is reported that the new airport will be ______ by the end of this year.A) completedB) completingC) to completeD) completes3. I would like to apologize for ______ you last night.A) disturbingB) disturbC) disturbedD) to disturb4. The teacher encouraged the students to ______ their questions.A) askB) askingC) asksD) to ask5. He felt ______ when he saw his name on the list of honor roll students.A) surprisedB) surprisingC) surprisedlyD) to surprise6. The company is planning to ______ its production capacity to meet the increasing demand.A) expandB) expandingC) to expandD) expanded7. We should ______ more attention to our health as we get older.A) payB) payingC) to payD) paid8. The government has taken measures to ______ the pollution in the area.A) reduceB) reducingC) to reduceD) reduced9. The students were ______ when they received the news of their admission to the university.A) excitedB) excitingC) excitedlyD) to excite10. The experiment was ______ by the team leader.A) conductedB) conductingC) to conductD) conducteded11. The doctor advised the patient to ______ more rest.A) takeB) takingC) to takeD) took12. She was ______ when she realized she had lost her wallet.A) frightenedB) frighteningC) frighteninglyD) to frighten13. The book is ______ by many readers as a classic.A) consideredB) consideringC) to considerD) considereded14. The teacher praised the students for their ______ in the exam.A) performanceB) performingC) to performD) performed15. The company has been ______ for its innovative products.A) praisedB) praisingC) to praiseD) praisableSection B (15 points)Complete the following sentences with the appropriate forms of the given verbs in brackets.1. The weather is so hot; I (be) going to the beach this weekend. (go)2. The meeting will start at 9 o'clock; we (wait) for the guests to arrive. (wait)3. She (not finish) her homework yet; she still has a lot to do. (finish)4. He (not see) his friend for a long time; they are planning to meet soon. (see)5. They (plan) to go hiking next weekend; it will be a great adventure. (plan)Part III Reading Comprehension (40 points)Section A (20 points)Read the following passage and answer the questions below.The rise of the internet has dramatically changed the way we consume media. In the past, people had to rely on traditional media sources such as newspapers, magazines, and television to stay informed. Today, with just a few clicks, we can access a wealth of information from around the world. This shift has had a significant impact on the media industry.One of the most noticeable changes is the decline in newspaper circulation. As more people turn to online news sources, newspapers have been forced to adapt. Many have shifted their focus to digital platforms, offering online subscriptions and digital editions. However, this hasnot been enough to offset the loss of print readership.The rise of social media has also had a profound effect on the media landscape. Platforms like Facebook, Twitter, and Instagram have become powerful tools for news dissemination. They allow users to share stories, opinions, and videos with their networks, which can rapidly spread information. However, this has also led to concerns about the spread of misinformation and fake news.Moreover, the internet has given rise to new media formats such as podcasts and online video content. These formats have provided new opportunities for creators to reach audiences. However, they have also created a more fragmented media landscape, with audiences fragmented across various platforms.Despite these challenges, the internet has also brought about several benefits. It has democratized access to information, allowing people to consume news and media from a wide range of sources. It has also enabled new forms of storytelling and creative expression.Questions:16. What is the main topic of the passage?A) The decline of traditional media.B) The rise of social media.C) The impact of the internet on the media industry.D) The benefits of online news.17. According to the passage, what has been the most significant change in the media industry?A) The rise of podcasts.B) The decline in newspaper circulation.C) The spread of misinformation.D) The fragmentation of the media landscape.18. Which of the following is NOT mentioned as a challenge of the internet in the media industry?A) The decline in newspaper readership.B) The spread of fake news.C) The rise of new media formats.D) The democratization of information.Section B (20 points)Read the following passage and complete the summary with the information given in the passage.________ (Para. 1: Introduction)________ (Para. 2: The impact of the internet on newspapers)________ (Para. 3: The rise of social media)________ (Para. 4: The impact of new media formats)________ (Para. 5: The benefits of the internet)Summary:The internet has transformed the media industry in numerous ways. It has caused a decline in newspaper circulation and led to the rise of social media platforms. Additionally, the internet has facilitated the growthof new media formats such as podcasts and online video content. Despite the challenges, the internet has democratized access to information and provided new opportunities for storytelling and creative expression.Part IV Writing (15 points)Write an essay of about 150-200 words on the following topic:How has technology changed the way we communicate with each other?You should use your own ideas, knowledge, and experience and supportyour argument with examples.Note: This is just a sample essay; the actual essay should be written by the candidate.Technology has significantly transformed the way we communicate with each other. In the past, communication was limited to face-to-face interactions, letters, and phone calls. Today, with the advent of the internet and mobile technology, communication has become faster, more convenient, and more diverse.One of the most notable changes is the rise of social media platforms. These platforms have revolutionized the way we share information, photos, and videos with our friends and family. We can now stay connected with people across the globe in real-time, sharing our daily lives and experiences.Moreover, the internet has made communication more accessible and cost-effective. Email, instant messaging, and video conferencing havereplaced traditional forms of communication, making it easier to communicate with others regardless of their location. This hasparticularly benefited businesses, which can now conduct international meetings and negotiations without the need for travel.However, technology has also brought about challenges, such as privacy concerns and the potential for misinformation. It is crucial to use these tools responsibly and be aware of their limitations.In conclusion, technology has had a profound impact on the way we communicate. While it has brought about many benefits, it is essential to be mindful of its potential drawbacks.。

English presentation of media bias 英文演讲-媒体偏差

Good morning fellow student and Mrs. Gilmour. News media plays an important role in society and most readers expect what is being reported to be the truth. Journalists use difference words, language features, visual images and quotes to empower or disempower specific groups or individuals. Today, I'll be deconstructing and evaluating two online news articles about the scandal of Baby Gammy to demonstrate how journalists represent the same issue in different ways to skew readers’ perceptions.Recently, a tragic and shocking story happened in Australia and Thailand which was due to an unregulated surrogacy system. The victims that were harmed the most by this scandal was a Down syndrome baby called Gammy who was abandoned by his Australian biological parents, while they took his healthy twin sister back to Australia.The first article I will discuss was published in the Sydney Morning Herald, August 10th 2014, under the headline “Thai surrogate baby Gammy was a victim of an unregulated world”. The journalist, Charles Waterstreet, outlined research revealing the ethical errors of commercial surrogacy. The article is supported by a noticeable image of the Thai surrogate mother holding and kissing the tiny baby who has Down syndrome. The whole picture looks very cozy if it wasn’t in context, and the caption underneath also informs the readers of more details about the situation of the baby right now. “An unfettered surrogacy market could create a situation in which on one takes responsibility for Gammy.” This caption supports Charles’ opinion that the main cause of Baby Gammy’s issue was an unconstrained surrogacy. Charles employs inclusive language, “now we are using Thai women to incubate our babies”, which demonstrates how the Australian population objectifies Thai woman as it uses them solely for the production of babies for their own gain.Through these languages Charles used, he skews readers’perceptions towards the Australian couple’s side. In the whole article, the journalist hasn’t talked a lot about the terrible thing the Australian couples have done. Whereas the second article focuses more on morally responsibility of the Australian couples and the solution of this event.The second article I’m covering today is published on .au, August 4th, 2014. This article is titled “Australian couple claim they are not the parents of baby Gammy – born to a Thai surrogate”. The headline clearly shows the irresponsibility of the Australian parents. It is interesting that the journalist starts the article with a picture of baby Gammy but not a text. The naive face of the baby evokes the reader’s sympathy and emphasises the power of the message the journalist is conveying. The journalist also uses quotes from the Australian immigration Minister Scott Morrison who states baby Gammy will be eligible for Australian citizenship. Mr. Scott also describes the surrogate mother Miss Chanbua as an “an absolute hero” and “a saint”. This high praise from Australian immigration department clarifies Australian government’s assistants to Miss Chanbua and baby Gammy.I believe the second article is more accurate and fairer than the first, as it employs many reliable quotes and also announces the solution to solve this case. The direct quotes from the Australian couple and surrogate mother point out the underlying causes and factors of this issue. Whereas the first article talks more about the journalist’ view and his stories that are not direct related to this issue. The first article also includes a very critically comment on Thai surrogacy rather than objectively, and there’s anything about the surrogate mother who is also a victim from this event. Due to this, the first article has the tendency to uphold a one-sided opinion. Overall, the languages and structural choices the journalists used in the articles can position readers’ perception differently.To some extent, news media delivers a fair, objective and accurate representation of the truth and current events. However, like the first article, some news Medias have imbalanced or unfair representations of the facts. From the evaluating and analysing of these two articles, it is clear that although some news media give lots of valuable information, journalists may have incentives to bias stories, especially if it is a scandal that involves a liberal issue. Due to this, readers should adjust their own beliefs based on the bias they anticipate and remain in a fair and objective perception of any events, individuals and groups.。

数字会带来运气英语作文

数字会带来运气英语作文English Answer:The belief that numbers hold mystical powers and can influence luck has been prevalent in various cultures throughout history. From the ancient Chinese numerological system to the modern-day practice of numerology in the West, numbers have been assigned symbolic meanings and associated with specific qualities and events.Numerological Systems.Numerous numerological systems have emerged over the centuries, each with its unique set of numerical correspondences and interpretations. One of the most well-known is the Chinese numerology system, known as "fourpillars of destiny." This system assigns numbers to the year, month, day, and hour of a person's birth and usesthem to calculate a person's life path, personality traits, and potential for success.In Western numerology, numbers are also assigned vibrational qualities and associated with specific themes and life experiences. For example, the number 3 is often associated with creativity and communication, while the number 7 is linked to spirituality and introspection. Some numerologists believe that certain numbers can enhance or hinder a person's luck depending on their individual numerological chart.Lucky Numbers.Across different cultures, various numbers are considered lucky or auspicious. In Chinese culture, the number 8 is highly prized as it symbolizes prosperity, wealth, and good fortune. The number 9 is also considered fortunate as it represents longevity and completeness. In Japan, the number 7 is considered lucky due to its association with the seven gods of fortune.Conversely, some numbers are associated with bad luck. In many Western cultures, the number 13 is often avoideddue to its association with superstition and misfortune. In Chinese culture, the number 4 is considered unlucky as it sounds similar to the word for death.Numerology in Practice.Numerology is often used to guide people in making important decisions, such as choosing a partner, starting a business, or investing in a new venture. Some people believe that by understanding their numerological profile, they can gain insights into their strengths, weaknesses, and potential for success. Numerology can also be used to predict future events or identify opportunities for growth.Skepticism and Scientific Evidence.While numerology remains a popular practice, there is no scientific evidence to support the claims that numbers hold any inherent power or influence over luck. Skeptics argue that the belief in lucky numbers is based on subjective experiences and confirmation bias, where people tend to remember positive outcomes associated with certainnumbers while ignoring negative ones.Cultural Significance.Despite the lack of scientific evidence, the belief in lucky numbers continues to hold cultural significance in many societies. It serves as a way for people to express their hopes and aspirations, and to create a sense of order and meaning in an often unpredictable world. Whether one believes in the power of numbers or not, the fascination with lucky numbers is an intriguing cultural phenomenonthat reflects the human desire for luck and prosperity.中文回答：数字会给人们带来好运的信念在历史上多种文化中都很盛行。

考研英语(一201)研究生考试试题与参考答案(2025年)

2025年研究生考试考研英语(一201)复习试题与参考答案一、完型填空（10分）Part A: Cloze TestFor each blank in the following passage, choose the best answer from the given options. Read the passage carefully before making your choices.The internet has become an integral part of our daily lives, transforming the way we communicate, work, and access information. Its impact on society is immense, and it continues to evolve at a rapid pace. The following passage discusses some of the challenges and opportunities that arise from this digital revolution.1.The internet has revolutionized the way we communicate, making it possible to connect with people all around the world 1_____.a) within secondsb) through traditional mailc) with the help of telephonesd) by using ancient means2.Social media platforms have 2_____ the number of online interactions and have become a powerful tool for social networking.a) diminishedb) increasedc) remained stabled) decreased3.One of the primary challenges of the digital age is the 3_____ of information overload.a) abundanceb) scarcityc) diversityd) precisionpanies are using big data analytics to 4_____ customer preferences and improve their services.a) predictb) ignorec) eliminated) overlook5.The rise of e-commerce has 5_____ the way we shop, offering convenience and a wider variety of products.a) transformedb) complicatedc) simplifiedd) eliminated6.While the internet has brought numerous benefits, it has also given riseto issues such as 6_____.a) improved educationb) increased job opportunitiesc) cybersecurity threatsd) better healthcare7.Online learning platforms have made education more accessible, allowing students to 7_____ courses from the comfort of their homes.a) submitb) participate inc) purchased) donate8.The rapid development of artificial intelligence has sparked 8_____ about the future of work and the potential displacement of jobs.a) excitementb) optimismc) concernd) indifference9.Internet privacy is a growing concern, with many users feeling that their personal data is not 9_____.a) secureb) accessiblec) sharedernments around the world are working to 10_____ internet regulations to ensure a safe and secure online environment.a) establishb) dismantlec) modifyd) ignore11.The internet has 11_____ the way we consume news, with many people relying on social media for updates.a) enrichedb) diminishedc) diversifiedd) consolidated12.One of the biggest advantages of the internet is its 12_____ in terms of information sharing and collaboration.a) limitationsb) benefitsc) challengesd) costs13.Online communication can sometimes lead to misunderstandings due to a lack of 13_____.a) clarityc) privacyd) access14.Cybersecurity experts are constantly working to 14_____ new threats and vulnerabilities.a) addressb) createc) ignored) eliminate15.The internet has 15_____ the global economy, facilitating international trade and business operations.a) boostedb) weakenedc) stabilizedd) diversified16.One of the challenges of the digital age is the 16_____ of digital literacy skills.a) shortageb) abundancec) diversityd) uniformity17.The internet has 17_____ the boundaries of traditional education,allowing for more personalized learning experiences.a) expandedb) narrowedc) maintainedd) eliminated18.While the internet offers numerous benefits, it also presents 18_____ in terms of mental health and well-being.a) opportunitiesb) challengesc) distractionsd) advancements19.Many people argue that the internet has 19_____ our attention spans, making us more prone to multitasking and shorter attention spans.a) extendedb) decreasedc) maintainedd) diversified20.Despite its challenges, the internet remains a powerful tool that has the potential to 20_____ our lives in countless ways.a) enrichb) degradec) isolated) confineAnswers:1.a) within seconds2.b) increased3.a) abundance4.a) predict5.a) transformed二、传统阅读理解（本部分有4大题，每大题10分，共40分）First QuestionPassage:“The Evolution of the English Language”The history of the English language is typically divided into three periods: Old English (approximately 450 to 1100 AD), Middle English (1100 to 1500), and Modern English (from 1500 to the present day). The language spoken during the Old English period was very different from the English we use today; it was heavily influenced by Germanic languages due to the Anglo-Saxon invasions. After the Norman Conquest in 1066, French became the language of the royal court and the ruling classes, which led to a significant number of French words being incorporated into the English vocabulary.During the Middle English period, the language began to take on a more familiar form as the influence of Latin and French from the Church and the Normansblended with the existing Germanic base. This period also saw the Great Vowel Shift, a major change in pronunciation that started around the 15th century and continued through the 17th century, transforming the sound system of the English language.Modern English emerged as a result of various linguistic changes and innovations, including the invention of the printing press, which standardized spelling, and the Renaissance, which introduced many Greek and Latin terms into the language. Today, English continues to evolve, absorbing new words from cultures all over the world, reflecting the globalized nature of our society.1、What were the main influences on Old English?A) Latin and FrenchB) French and ItalianC) Germanic languages and LatinD) Germanic languages and French2、When did the English language begin to shift significantly towards its modern form?A) After the Norman ConquestB) Around the 15th centuryC) During the RenaissanceD) In the 18th century3、Which event is credited with standardizing English spelling?A) The Norman ConquestB) The Great Vowel ShiftC) The invention of the printing pressD) The Renaissance4、What does the passage suggest about the current state of the English language?A) It is no longer evolving.B) It has stopped borrowing words from other languages.C) It remains static and unchanged since the Middle English period.D) It is continuing to evolve and incorporate new words from various cultures.5、Which of the following best describes the impact of the Great Vowel Shift?A) It introduced French vocabulary into English.B) It led to changes in the pronunciation of English vowels.C) It standardized the spelling of English words.D) It marked the beginning of the Old English period.Answers:1、D2、B3、C4、D5、B第二题Read the following passage and answer the questions that follow.The advent of the internet has revolutionized the way we access information and communicate with others. From the early days of dial-up modems to the lightning-fast speeds of today’s 5G n etworks, the internet has grown exponentially. This rapid expansion has not only brought about convenience but also raised concerns about privacy and security.1.The passage discusses the impact of the internet on:a)Educationb)Communicationc)Entertainmentd)Transportation2.The phrase “revolutions the way we access information” suggests that the internet has:a)Made information less accessibleb)Had no impact on information accessc)Made information more accessibled)Brought about confusion in information access3.The term “exponentially” implies that the growth of the internet has been:a)Slow and steadyb)Unpredictablec)Very fast and intensed)Gradual and consistent4.The passage mentions that the internet has brought about both convenience and concerns. Which of the following is NOT mentioned as a concern?a)Privacy issuesb)Security breachesc)Increased traffic congestiond)Loss of face-to-face interactions5.The author’s tone towards the internet can be described as:a)Highly criticalb)Indifferentc)Positive and optimisticd)Negative and skepticalAnswers:1.b) Communication2.c) Made information more accessible3.c) Very fast and intense4.c) Increased traffic congestion5.c) Positive and optimisticThird QuestionPassage:In today’s fast-paced world, technology has become an indispensable part of our lives. It shapes how we communicate, learn, and even entertain ourselves. One area where technology has made significant strides is in education. The advent of e-learning platforms has revolutionized traditional classroom settings, making education more accessible and flexible than ever before.However, the integration of technology into education is not without its challenges. Critics argue that excessive reliance on technology could lead toa decrease in face-to-face interaction among students, potentially weakening their social skills. Moreover, there is concern about the digital divide, which refers to the gap between those who have ready access to digital technology and those who do not. This disparity can exacerbate existing educational inequalities if not properly addressed.Despite these concerns, proponents of educational technology believe that the benefits far outweigh the drawbacks. With the right policies in place to ensure equitable access and usage, technology can serve as a powerful tool to enhance learning experiences and outcomes.Questions:1、What is one major benefit of integrating technology into education according to the passage?Answer: The major benefit mentioned is that technology makes education more accessible and flexible through e-learning platforms.2、What potential drawback of technological integration into education is mentioned?Answer: A potential drawback is the decrease in face-to-face interactions among students, which might weaken their social skills.3、How does the passage define the term “digital divide”?Answer: The “digital divide” is defined as the gap between those who have ready access to digital technology and those who do not.4、What concern is raised regarding the digital divide in the context ofeducation?Answer: The concern is that the digital divide could exacerbate existing educational inequalities.5、According to the passage, what condition must be met to harness the full benefits of educational technology?Answer: The condition stated is that there need to be right policies in place to ensure equitable access and usage of technology.第四题Reading Passage:In the era of digital technology, the importance of traditional reading skills has often been overlooked. However, reading traditional books offers numerous benefits that cannot be replicated by digital devices. This passage discusses the advantages of reading traditional books over digital ones.The benefits of reading traditional books are multifaceted. Firstly, it enhances cognitive development. The physical act of turning pages and holding a book requires more engagement from the reader, which leads to better concentration and comprehension. Secondly, reading traditional books promotes relaxation and reduces stress. The tactile experience of holding a book and the soothing sound of pages turning create a calming atmosphere that is conducive to relaxation. Thirdly, traditional books offer a unique sense of ownership and connection. Collecting books and having them on a shelf creates a personal library that is a reflection of one’s personality and interests. Lastly,traditional books have a longer lifespan than digital devices, making them a more sustainable choice.Despite the numerous benefits of reading traditional books, the rise of digital technology has led to a decline in book reading. Many people now prefer to read on e-readers or smartphones, which are more convenient and portable. However, this convenience comes at a cost. E-readers and smartphones can be addictive, leading to shorter attention spans and reduced concentration. Additionally, the screen glare and blue light emitted by digital devices can be harmful to one’s eyes and overall health.The importance of traditional reading skills cannot be overstated. Reading traditional books offers numerous benefits that contribute to cognitive development, relaxation, personal connection, and sustainability. While digital technology has its advantages, it is crucial to maintain the habit of reading traditional books to reap these benefits.Questions:1、What is the main advantage of reading traditional books mentioned in the passage?A. They are more portable.B. They enhance cognitive development.C. They are more convenient.D. They are more sustainable.2、According to the passage, how does reading traditional books contributeto relaxation?A. It provides a soothing sound of pages turning.B. It enhances cognitive development.C. It promotes social interaction.D. It helps in reducing stress.3、What is one of the unique benefits of traditional books mentioned in the passage?A. They have a longer lifespan than digital devices.B. They can be easily shared with others.C. They are more durable than digital devices.D. They offer a personal sense of connection.4、Why does the passage mention the decline in book reading?A. Because digital technology is more convenient.B. Because traditional books are more expensive.C. Because people prefer to read on e-readers.D. Because traditional books are less accessible.5、What is the author’s main argument in the passage?A. Traditional books are better than digital devices.B. Digital technology is more beneficial for reading.C. Traditional reading skills are important to maintain.D. Digital devices are more sustainable than traditional books.Answers:1、B2、A3、D4、A5、C三、阅读理解新题型（10分）Section III Reading Comprehension (New Type)Part ADirections: There is a passage in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A), B), C), and D). You should decide on the best choice and mark the corresponding letter on Answer Sheet 2 with a single line through the centre.Passage:The rise of the Internet and the spread of social media have dramatically changed the way we communicate and interact with each other. One of the most significant impacts of these technologies is the transformation of traditional media, which has led to the emergence of new forms of media and communication. This shift has not only altered the way we consume information but also the way we create and share it.The traditional media landscape, dominated by newspapers, television, and radio, has been rapidly reshaped by the digital age. These platforms have adaptedto the digital environment, offering users more personalized and interactive experiences. However, the rise of digital media has also brought challenges, such as the spread of misinformation and the decline in the quality of content.One of the most notable developments in digital media is the rise of influencers. Influencers are individuals who have established a significant online presence and have gained a loyal following. They often use their platforms to promote products, services, or ideas, and their influence can be significant. The power of influencers lies in their ability to reach a large audience quickly and effectively.Despite the benefits, the influence of digital media and influencers raises important ethical and social questions. The spread of fake news, for instance, is a direct consequence of the rapid dissemination of information online. Moreover, the influence of influencers can sometimes lead to harmful behaviors, such as the promotion of unrealistic body image or the encouragement of materialism.The impact of digital media on society is multifaceted. It has democratized information, allowing individuals to access and share knowledge more easily than ever before. However, it has also created new forms of inequality, such as the digital divide, where individuals without access to the internet are left behind.Questions:1.What is the main topic of the passage?A) The rise of digital mediaB) The decline of traditional mediaC) The rise of influencersD) The impact of digital media on society2.According to the passage, what is one of the challenges brought by the rise of digital media?A) The increase in the quality of contentB) The spread of misinformationC) The decrease in the number of traditional media platformsD) The increase in the number of influencers3.Which of the following is NOT mentioned as an ethical or social question raised by the influence of digital media?A) The spread of fake newsB) The promotion of unrealistic body imageC) The increase in the number of newspapersD) The encouragement of materialism4.What is the author’s attitude towards the democratization of information by digital media?A) SkepticalB) NeutralC) SupportiveD) Critical5.The passage suggests that the digital divide can result in:A) More people having access to informationB) Less people having access to informationC) No change in the access to informationD) A more equal distribution of informationAnswers:1.D) The impact of digital media on society2.B) The spread of misinformation3.C) The increase in the number of newspapers4.C) Supportive5.B) Less people having access to information四、翻译（本大题有5小题，每小题2分，共10分）第一题Translate the following Chinese paragraph into English.中文段落：“近年来，随着科技的飞速发展，人们的生活方式发生了翻天覆地的变化。

人工智能机器学习技术练习(习题卷20)

人工智能机器学习技术练习(习题卷20)第1部分：单项选择题，共58题，每题只有一个正确答案,多选或少选均不得分。

1.[单选题]如果我们说“线性回归”模型完美地拟合了训练样本（训练样本误差为零），则下面哪个说法是正确的？A)测试样本误差始终为零B)测试样本误差不可能为零C)以上答案都不对答案:C解析:根据训练样本误差为零，无法推断测试样本误差是否为零。

值得一提是，如果测试样本样本很大，则很可能发生过拟合，模型不具备很好的泛化能力！2.[单选题]关于回归问题,说法正确的是()A)可以不需要labelB)label列是连续型C)属于无监督学习答案:B解析:3.[单选题](__)不属于基本分析方法。

A)回归分析B)分类分析C)聚类分析D)元分析答案:D解析:4.[单选题]下列对于查全率的描述，解释正确的是（__）。

A)统计分类器预测出来的结果与真实结果不相同的个数，然后除以总的样例集D的个数。

B)先统计分类正确的样本数，然后除以总的样例集D的个数。

C)预测为正的样例中有多少是真正的正样例D)样本中的正例有多少被预测正确答案:D解析:5.[单选题]n!后面有多少个0,6!=1*2*3*4*5*6=720.720后面有1个0,n=10000,求n!。

A)2498B)2499C)2450D)2451答案:B解析:6.[单选题]以下不属于线性分类器最佳准则的是( )A)感知准则函数B)支持向量机C)贝叶斯分类D)Fisher准则解析:7.[单选题]以下对字典的说法错误的是（）。

A)字典可以为空B)字典的键不能相同C)字典的键不可变D)字典的键的值不可变答案:D解析:8.[单选题]假设我们有一个使用ReLU激活函数(ReLU activation function)的神经网络，假如我们把ReLU激活替换为线性激活，那么这个神经网络能够模拟出同或函数(XNOR function)吗( )A)可以B)不能C)不好说D)不一定答案:B解析:9.[单选题]关于欠拟合(under-fitting),正确的是( )。

营销混合模型（MMM）手册：开发有影响力的营销混合模型的指南说明书

There is more to measurement strategies than the science behind the model. Incorporating business context to shape an MMM is an art — one with implications for the model’s outcomes and financial recommendations. Advertisers who embrace that art can empower their businesses to make more strategic measurement-based decisions.The checklist below summarises key MMM best practises to ensure rigorous model design.Click on each section to explore related checklists:Start with the right questionsthe first time , refer to this checklist when discussingmethodology with potential partners and internal marketingscience or data science teams. Check off all best practicesthat you consider important for your business.If you have already started your MMM journey, check offall best practices already included in your models andconsider discussing the remaining ones with your MMMteam and partners.While it can be tempting to start the conversation aboutMMM with methodology, it is more beneficial to begin withbusiness questions and then choose the best approach toanswer them. MMM may not be able to answer all yourquestions, so identifying the limitations of your plannedMMM solution will help you manage expectations and findcomplementary solutions.Basic:Yes No UnsureAdvanced:Yes No UnsureWhat percentage of total sales is driven by each marketing channel?How does the sales contribution from each channel compare to its share of investment?How do non-media factors contribute to sales?What percentage of sales would be lost if all media investments were cancelled?Does digital media drive offline sales?What is the historic ROI for each media channel?What is the marginal ROI for each media channel?What is the recommended budget allocation for each channel?Which tactics (creative, targeting, ad formats) contribute most to my media profitability?What are the direct and indirect effects of media channels?How does my media drive both short and long-term sales?How do media channels compare in their ability to drive sales and brand outcomes?How do I balance my media mix to drive both short and long-term sales?What are the synergies between media channels?Accurate marketing mix models recognise thatdifferent media campaigns drive different outcomes.While some campaigns drive brand perceptions,others generate leads or drive sales online or offline.Today, it is not uncommon to see MMM built aroundseveral KPIs via a model design called structuralequation modelling, also known as nested models.Nested models measure the impact on more thanone KPI. For example, if brand-building campaignsare designed to drive brand preference, a brandpreference index from a brand tracker would be theideal outcome to measure in the model alongsidesales. Sometimes continuous data for brand index isnot available. In this case, proxies can be used suchas Share of Search.Which of the following KPIs are (planned to be) included in your MMM? Mark your answers with aYes No Unsure Yes No UnsureOnline salesOffline salesTotal salesOnline action (leads, subscriptions,contracts, orders, etc.)Offline actionsTotal actionsVisit to siteShare of SearchGoogle query volumePurchase intentBrand considerationBrand preference/likingBrand awarenessA distinctive strength of MMM over other media effectiveness measurement solutions is the flexibility of model design and its ability to include outcomes and drivers that are relevant to the business while measuring all these relationships in the same analysis. If there is uncertainty about whether sales are impacted by an event or specific factor, MMM can confirm the impact by testing the relationship between the outcomes and potential drivers and, when a relationship is confirmed, estimate the strength of this relationship. With that in mind, it is important to be diligent in designing a comprehensive model by including all possible outcome drivers.Traditionally, an MMM aimed to capture the impact of marketing on bottomline outcomes only: sales, transactions, or subscriptions. As more brands embraced full-funnel marketing, it became important to measure campaigns based on the job they were created for and to recognise that not all campaigns are designed to drive sales. Some marketing activity is reserved for building brand strength.Luckily, brand measurement has existed for some time, with an ecosystem of brand tracking providers offering customer surveys that measure the share of the audience that is aware of the brand (brand awareness), has a positive mindset around it (preference) and intends to buy it (consideration or purchase intent). Modern MMM increasingly focus on the multi-functionality of media, measure impact on outcomes across the customer journey, and can even link media, brand strength and sales.Which factors do you (plan to) include in your MMM?Mark your answers with aYes No UnsureMedia support by channelPrice changesDistribution, if applicable (e.g.number of stores)External events (e.g. COVID-19)Economic factors, if applicable (gasprices, confidence index, other)WeatherSeasonality Yes No UnsureCompetitive mediaCompetitive price changesProduct launchesOther intermediate outcomes(Google query volume, share ofSearch, site traffic)Brand outcomes (brandawareness, consideration,preference)You’ve probably heard the expression “garbage in,garbage out” — this is very true in MMM. While data hasgenerally become more accurate and detailed thanks tonew data collection and storing and management tools, itshould not be taken for granted that data accuracy andgranularity are the foundationof a robust MMM.Receiving media data from trusted sources, such as theGoogle MMM data request tool, can help ensure dataaccuracy and completeness. It is a best practice tovalidate data by comparing a high-level summary (e.g.impressions or investment) with a similar summary fromother sources, regardless of the method used to extractthe data.One of the most common criticisms of MMM is that theresults it produces are not detailed enough. For example,channel-level ROIs can help make the right decision tobalance budgets, but without campaign or tactic-levelROIs, marketers do not know what drives channelperformance and how to improve the overall channelROI. In contrast, channel performance by target, creative,or even optimisation method can help identify whichtactics work better than others. The savviest marketersdifferentiate campaigns by their marketing objectivesand measure their effectiveness on the relevant KPIswithin an MMM.While designing models for granularity, it is important to be aware of the risk of “over-fitting the model”, which occurs when too many variables are included and the reliability of the model is sacrificed. One way to overcome this challenge is to rise the upper limit of the number of input variables by increasing the number of data points in the modeled KPI. he most common way of doing this is by segmenting all data by, for example, geographical areas or product segments, and stacking those segments in the modelled dataset.Another obstacle to granularity can be the nature of media campaigns: multiple channels can be used simultaneously, leading to correlation of inputs. This compromises the accuracy of attributionof impacts on sales between correlated channels. Sometimes the only reliable way to measure such channels is to combine them in one input.Mark your answers with a Yes No UnsureMy media data... is extracted from trusted sources.is validated by comparing totals or trends with a different source.splits tactics by channel.splits tactics by creative.splits tactics by targeting.splits tactics by marketing objectives.“The savviest marketers differentiate campaigns by their marketing objectives and measure their effectiveness on therelevant KPIs within an MMM.”MMM have been around for over five decades and this existence has resulted in a body of best practices that lean on proven relationships. It is most important that you know what you aremodelling and understand how media works. Digital channels offer a greater variety of formats, targeting, and optimisation options than traditional channels.Seeing an ad today may result in a purchase decision a week from now. Carryover is a type of transformation from the original media input (e.g. impressions) in order to better represent the staying power of ads.Since most media campaigns run over time, ranging from several days to weeks, the carry-over effect from each day of the campaign must be added to the immediate effects in the subsequent days. Media inputs need to be transformed to account for this effect. This is called the adstock effect.As advertisers continue to increase investments in a media channel, the channel nears the point where it has influenced all the people it could. The closer the investment levels to this point, the lower the return is on investment. This is called diminishing returns . Media inputs need to be transformed to account for this effect.The level of granularity has a big impact on the calculated ROIs from MMM. Generally speaking, more media inputs (e.g. by campaign, creative, bidding strategy, or target audience) produce more accurate results by providing a differentiated view of the performance for each of these tactics.“'Carryover' is a type of transformation from the original media input in order tobetter represent the staying power of ads.”Understanding the terminology“Th e nested model approach can calculate the sum of the short and long-term sales ROI, where the impact via improving brand KPIs is measured.”One of the key considerations for measuring the ROI of upper-funnel or brand building channels is capturing total ROI, which is the sum of the short and long-term sales ROI. The latter can be calculated using a nested model approach, where the direct impact on sales and the indirect impact via improving brand KPIs are measured.The types of inputs used to represent a channel also make a significant difference. For example, some studies show that branded search modelled with clicks instead of impressions show a significantly different ROI for branded search, while the difference is less noticeable for generic ads and shopping ads.I t is up to the modeller's discretion to use clicks or impressions as inputs in the model, but it is recommended to avoid using costs as input variables, as this can lead to misleading results. Costs can vary based on targeting, advertiser's, and competitors’ bidding strategies, and can cause misrepresentation of ad effectiveness.Changes in media strategy are common and frequent in digital media. Moreover, our account teams work relentlessly to help advertisers optimise their media. Therefore, it is important to recognise that media ROI is expected to change over time. As a result, it is recommended to use campaign-level inputs wherever possible or to distinguish between time periods when a channel-level variable must be used to detect the changes in media ROI over time.Finally, no model is perfect. Each model will have its own set of limitations in capturing digital channels, such as:•Collinearity: e.g. YouTube is flighted at exactly the same time as TV ads•Low levels of spend may cause lack of a detectable ROI•Lack of variation (common in always-on campaigns) may cause a lackof detectable ROIEach media channel has its own differentiated carryover effect.Each channel input has been transformed to account for adstock.Each media channel has been transformed to account for diminishing returns.We and our modelling partners understand digital media channels and how to identifywhich part of the customer journey they address based on creative, formats, targeting,and bidding or buying strategy.Our models capture digital media channels’ effectiveness at sub-channel level (bycreative, targeting, or campaign).Our digital media channels are captured with impressions, clicks, or views instead of cost.Our models are designed to capture direct and indirect effects of media.Media ROI is differentiated by time periods via cutting variables in intervals in the model or grouping campaigns by time period in ROI calculations.Our modelling partners have explored and shared with us the model’s limitations which are considered in forming recommendations.Our model is based on additive multivariate regression.Our model is based on multiplicative multivariate regression.Our model is based on Bayesian approach.Do you apply these best practices to digital channels in your MMM?Mark your answers with aYes No UnsureIt is important to take note of the model’s limitations and keep them in mind when turning MMM results into insights and budget recommendations. Sometimes model limitations lead to supplementary analyses for a more conclusive result, or at least caution when acting on the model’s insights.10Do you receive the below outputs or services from your MMM partner?Mark your answers with aYes No UnsureHistoric ROIs (past return on investment).Marginal ROIs (return on the next $1 invested).Response curves (also known as saturation curves).Hypotheses as to which factors influenced media ROIs.Budget optimisation scenarios.Recommended actions outside of the media budgets.ROIs by channel.ROIs by ad format.ROIs by creative.ROIs by targeting.ROI by bidding strategy or buy model, e.g. CPM, CPV, CPA (if applicable).Clear and informative charts and data visualisations.Explanation of the model results and consultation.11While marketing mix modelling has a high degree ofversatility in what KPIs it can analyse and whichfactors can be included, it also has an importantlimitation — it cannot handle a high number of inputvariables which precludes deep granularity of results.To meet this challenge, a blended methodologyapproach is leveraged by some advertisers, mergingattribution and MMM to augment results with moregranular media insights at a tactical level.One common point of criticism of MMM is the factthat it is not causal in nature, but based on correlation.There are ways to test for causality within MMM but itcan also be identified by combining MMM with other tactics, such as geo experiment or incrementality testing. Such approaches can also help calibrate the incremental volumefrom MMM.Yet another way to take an MMM to the next level is to enrich the design or the insights with campaign-level measurements such as brand lift studies that measure changes in a brand KPI due to exposure to media on YouTube. This approach helps link improvements in brand KPIs to sales.Which analyses do you currently supplement your MMM with?Mark your answers with aYes No Unsure Yes No UnsureAttribution Experiments Brand lift studies Test-and-learn programsOther12。

measurement

measurementMeasurementIntroductionMeasurement is a fundamental concept in science and everyday life. It is the process of assigning numbers to objects or events based on certain rules or standards. This allows us to quantify and compare different phenomena, enabling us to make informed decisions and understand the world around us. In this document, we will explore the importance of measurement, different types of measurement scales, and the challenges associated with accurate and precise measurements.Importance of MeasurementMeasurement plays a crucial role in various fields, including science, engineering, medicine, economics, and social sciences. It provides a common language for communication and allows us to make predictions, evaluate hypotheses, and test theories. Accurate measurements are essential for quality control, ensuring the safety and efficacy of products and processes. In addition, measurements are used in research to collect data, perform statistical analysis, and draw meaningful conclusions.Types of Measurement ScalesThere are four main types of measurement scales: nominal, ordinal, interval, and ratio. Each scale has its own characteristics and implications for data analysis.1. Nominal Scale: This is the simplest form of measurement scale, where values are used to label or categorize objects or events without any quantitative significance. Examples include gender (male/female), marital status(single/married/divorced), and blood types (A/B/O). Nominal scales are usually used for identification purposes and do not allow for mathematical operations.2. Ordinal Scale: In an ordinal scale, values not only categorize but also provide a relative order or ranking to the objects or events being measured. However, the differences between the values are not precisely quantifiable. For example, a survey asking respondents to rate a product or service on a scale of 1 to 5 (1 = very poor, 5 = excellent) uses an ordinal scale. While it is possible to determine that one rating is higher than the other, the differences between the ratings may not be equal or meaningful.3. Interval Scale: An interval scale has all the characteristics of an ordinal scale but also has equal intervals between the values. This means that the differences between the values are quantifiable and meaningful. A classic example of an interval scale is the Celsius temperature scale, where the differences between each degree are equal. However, an interval scale does not have a true zero point, as zero does not represent the absence of the measured attribute. For instance, zero degrees Celsius does not mean the absence of temperature.4. Ratio Scale: The ratio scale is the most sophisticated type of measurement scale. It has all the features of an interval scale but also has a true zero point, which represents the absence of the measured attribute. Examples of ratio scales include height, weight, time, and distance. In ratio scales, ratios are meaningful, and mathematical operations such as addition, subtraction, multiplication, and division can be applied to the measured values.Challenges in MeasurementWhile measurement is crucial, obtaining accurate and precise measurements can be challenging due to various factors. Some common challenges include:1. Instrumentation: The accuracy and precision of measurement instruments play a significant role in obtaining reliable measurements. Using faulty or outdated equipment can lead to inaccurate results. Regular calibration and maintenance of instruments are necessary to ensure their accuracy.2. Human Error: Human error can introduce inaccuracies in measurements. Factors such as perceptual limitations, bias, and insufficient training can affect the reliability of measurements. Adequate training, careful observation, and following standardized procedures can help minimize human errors.3. Environmental Conditions: The environment in which measurements are taken can also influence accuracy. Variables such as temperature, humidity, and pressure can affect the behavior of objects or substances being measured. Controlling and monitoring environmental conditions can help mitigate these effects.4. Sampling Bias: In research, obtaining representative samples is crucial for generalizing results to larger populations. However, sampling bias can occur when the selected sample does not accurately represent the populationbeing studied. This can introduce errors and affect the validity of conclusions drawn from the measurements.ConclusionMeasurement is vital for understanding and quantifying the world around us. Different types of measurement scales allow us to categorize, rank, and quantify objects or events according to their attributes. However, obtaining accurate and precise measurements can be challenging due to various factors such as instrumentation, human error, environmental conditions, and sampling bias. Awareness of these challenges and implementing appropriate measures can help improve the quality and reliability of measurements.。

大数据理论考试(习题卷2)

大数据理论考试(习题卷2)第1部分：单项选择题，共64题，每题只有一个正确答案,多选或少选均不得分。

1.[单选题]最早被提出的循环神经网络门控算法是什么（）A)长短期记忆网络B)门控循环单元网络C)堆叠循环神经网络D)双向循环神经网答案:A解析:LSTM是最早被提出的循环神经网络门控算法。

长短期记忆网络（Long-Short Term Memory,LSTM）论文首次发表于1997年11月15日。

门控循环单元网络（GRU）论文发表于2014年。

堆叠循环神经网络（SRNN）论文发表于2017年。

双向循环神经网络（Bidirectional recurrent neural networks）发表于1997年11月。

2.[单选题]关于欠拟合（under-fitting），（）是正确的。

A)训练误差较大，测试误差较小B)训练误差较小，测试误差较大C)训练误差较大，测试误差较大D)训练误差较小，测试误差较答案:C解析:欠拟合是指对训练样本的一般性质尚未学好，因此训练误差和测试误差均较大3.[单选题]（）模块是python标准库中最常用的模块之一。

通过它可以获取命令行参数，从而实现从程序外部向程序内部传递参数的功能，也可以获取程序路径和当前系统平台等信息。

A)sysB)platformC)mathD)time答案:A解析:sys模块用来获取命令行参数，从而实现从程序外部向程序内部传递参数的功能，也可以获取程序路径和当前系统平台等信息。

4.[单选题]数据管理成熟度模型中成熟度等级最高是哪一级（）。

A)已优化级B)已测量级C)已定义级D)已管理级答案:A解析:已优化是数据管理成熟度模型中成熟度的最高等级。

5.[单选题]多分类学习中，最经典的三种拆分策略不包括（）。

A)一对一B)一对其余C)一对多D)多对多6.[单选题]属于卷积神经网络应用方向的是(__)。

A)图像分类B)目标检测C)图像语义分割D)以上答案都正答案:D解析:卷积神经网络应用于图像分类，目标检测及图像语义分割。

泛媒偏向论名词解释

泛媒偏向论名词解释
泛媒偏向论（Media Convergence Bias）是指由于不同媒体形式的融合和交互，媒体内容在传播过程中可能存在偏向性。

这种偏向性可能是由于特定媒体平台的所有者或控制者的立场、利益或意识形态所导致的。

在泛媒偏向论中，媒体的融合和交互可能导致信息的过度集中或过度筛选，从而影响了信息的客观性和多样性。

这种偏向可能会对公众的信息获取和认知产生影响，因此需要引起媒体从业者和公众的关注和警惕。

泛媒偏向论提醒我们在媒体使用和信息获取过程中要保持批判性思维，多方获取信息，避免单一媒体或信息源的影响。

网络流行度预测中的偏差与方差分析方法介绍(四)

网络流行度预测中的偏差与方差分析方法介绍在当今信息时代，互联网成为人们获取信息和沟通交流的主要渠道。

而网络上的内容流行度预测则成为社交媒体、电子商务等领域的重要问题之一。

然而，由于流行度受到多种因素的影响，如用户兴趣、社交网络结构等，导致预测准确性往往存在偏差与方差的问题。

本文将介绍偏差与方差分析方法，帮助解决网络流行度预测中的问题。

偏差（Bias）是指模型预测值与真实值之间的差异，表示模型的系统性错误。

在流行度预测中，常见的偏差原因包括但不限于：特征提取不准确、采样数据不全、模型选取不当等。

在解决偏差问题时，我们可以利用回归分析、深度学习等方法进行模型训练。

通过对特定领域的数据进行特征抽取，建立合适的机器学习模型，提高预测的准确性。

方差（Variance）是指模型在不同数据集上预测结果的差异，反映了模型的不稳定性。

在流行度预测中，方差问题主要由于数据的不确定性、样本数量不足等造成的。

为了解决方差问题，我们可以利用集成学习、交叉验证等方法来降低模型的方差。

其中集成学习可以将多个不同的模型融合在一起，通过取平均或加权的方式得到预测结果，从而减少模型的方差。

除了偏差与方差问题外，网络流行度预测还需要考虑数据的可解释性。

在实际应用中，我们不仅需要一个准确的预测模型，还需要能够解释模型的结果，帮助我们理解影响流行度的关键因素。

为了提高可解释性，我们可以利用可视化分析、解释性模型等方法来研究流行度的内在机制。

通过可视化分析，我们可以可视化出不同特征对流行度的影响程度，找出重要的影响因素。

而解释性模型则可以通过提供决策树、规则列表等输出结果，使得模型的预测结果更具可解释性。

此外，网络流行度预测还需要考虑时间序列的变化特征。

在实际应用中，流行度往往具有时间相关性，即某一内容的流行度在特定时间段内可能会有明显的波动。

为了解决时间序列的问题，我们可以引入时间序列分析方法进行预测。

时间序列分析以其独有的时间序列结构、滞后关系等特点，可以较好地对流行度的变化进行建模和预测。

保卷媒介分析期末总结

保卷媒介分析期末总结Introduction:Media analysis is a vital aspect of media recording, which involves the identification and examination of different media forms, contents, and structures. This process helps in understanding how media influences society and shapes individual opinions. This final summary will discuss the various components of media analysis and how they contribute to the overall understanding of media recording.Body:1. The Importance of Media Analysis:1.1 Media analysis helps in critically examining and understanding different media forms, such as print media, broadcast media, and online media.1.2 Media analysis examines the content, production techniques, messaging, and intended audience of media recordings.1.3 Media analysis helps in identifying biases, stereotypes, propaganda, and other factors that influence media productions.2. Components of Media Analysis:2.1 Media Form: Understanding the different media formats and their impact on society. This involves analyzing print media, broadcast media (television and radio), and online media (websites, social media platforms).2.2 Content Analysis: Analyzing the subject matter, themes, and messages conveyed through media recordings. This includes examining the language, visuals, and symbolism used in media productions.2.3 Production Techniques: Examining the production methods used in media recordings, such as camera angles, lighting, sound, and editing techniques. This analysis helps in understanding how these techniques contribute to the overall message of the recording.2.4 Audience Analysis: Understanding the intended audience of media recordings and how media producers target specific demographics. This involves examining the demographics, psychographics, and socio-cultural factors that influence audience reception.2.5 Social and Cultural Analysis: Examining how media reflects and shapes societal attitudes, values, and beliefs. This analysis helps in understanding the socio-cultural impact of media recordings and their influence on public opinion.3. Media Recording Examples:3.1 Print Media Analysis:3.1.1 Examination of newspaper and magazine articles, headlines, and advertisements.3.1.2 Analysis of publication layout, fonts, and visual elements.3.1.3 Critical evaluation of language usage, narrative techniques, and editorial biases.3.2 Broadcast Media Analysis:3.2.1 Examination of television news programs, documentaries, and reality shows.3.2.2 Analysis of camera angles, lighting, sound effects, and editing techniques used in TV shows or movies.3.2.3 Evaluation of news anchors, journalists, and their presentation styles.3.3 Online Media Analysis:3.3.1 Examination of social media platforms, websites, and blogs.3.3.2 Analysis of online news articles, viral videos, and advertisement campaigns.3.3.3 Evaluation of user-generated content, comments, and online communities.4. Challenges and Ethical Considerations in Media Analysis:4.1 Media Bias: Identification and management of personal bias while conducting media analysis.4.2 Ethical Considerations: Ensuring the privacy and consent of individuals featured in media recordings.4.3 Constantly Evolving Media Landscape: Keeping up with technological advancements and emerging media platforms for analysis.Conclusion:Media analysis plays a significant role in understanding media recording by examining its various components, such as form, content, production techniques, audience, and socio-cultural factors. Through critical analysis, media professionals and consumers can gain insights into how media influences society, shapes opinions, and impacts public discourse. Despite the challenges and ethical considerations involved, media analysis remains a valuable tool to ensure media literacy and critical engagement with media recordings.。

高三英语统计学分析单选题60题

高三英语统计学分析单选题60题1.The average of a set of numbers is also called the _____.A.medianB.modeC.meanD.range答案：C。

平均一组数字也被称为平均数（mean）。

中位数（median）是按顺序排列的一组数据中居于中间位置的数。

众数（mode）是一组数据中出现次数最多的数值。

极差（range）是一组数据中最大值与最小值之差。

2.In a data set, the middle value when the data is arranged in ascending order is called the _____.A.medianB.modeC.meanD.range答案：A。

在一组数据中，当数据按升序排列时中间的值被称为中位数 median）。

3.The value that occurs most frequently in a data set is known as the _____.A.medianB.modeC.meanD.range答案：B。

在一组数据中出现最频繁的值被称为众数 mode）。

4.The difference between the highest and lowest values in a data set is called the _____.A.medianB.modeC.meanD.range答案：D。

一组数据中最大值和最小值之间的差被称为极差range）。

5.Which of the following is a measure of central tendency?A.RangeB.VarianceC.MeanD.Standard deviation答案：C。

平均数（mean）是一种集中趋势的度量。

极差（range）是描述数据分散程度的。

方差（variance）和标准差（standard deviation）也是描述数据分散程度的。

媒体的力量干扰人们的决定英语作文

媒体的力量干扰人们的决定英语作文The Power of Media in Influencing People's DecisionsIntroduction:In today's digital age, the media plays a significant role in shaping public opinion and influencing people's decisions. From television to social media platforms, media outlets have the power to sway people's views on various subjects, ranging from politics to consumer choices. This essay aims to explore the ways in which the media exerts its influence on individuals and societies, and the implications of this power on decision-making processes.Impact of Media on Decision-making:One of the most prominent ways in which the media influences people's decisions is through the dissemination of information. News outlets can frame stories in a way that promotes a particular narrative, influencing how people perceive events and issues. For example, biased reporting during election campaigns can sway voters' opinions and impact their choices at the ballot box.Additionally, advertisements play a crucial role in shaping consumer behavior. Companies spend billions of dollars eachyear on marketing campaigns to persuade consumers to buy their products. From catchy jingles to emotional appeals, advertisers use various techniques to influence people's purchasing decisions.The rise of social media has further amplified the media's influence on decision-making. Platforms like Facebook and Twitter allow for the rapid spread of information, making it easier for certain messages to go viral. This can lead to the amplification of misinformation and the manipulation of public opinion on a large scale.Implications of Media Influence:While the media can be a powerful tool for raising awareness and sparking social change, its influence can also have negative consequences. The dissemination of fake news and misinformation can sow confusion and division among the public, leading to mistrust in institutions and eroding democratic principles.Moreover, the constant barrage of advertisements and sponsored content can create a culture of consumerism, where people are encouraged to buy products they don't need or can't afford. This can have serious consequences for individuals'financial well-being and contribute to unsustainable patterns of consumption.Conclusion:In conclusion, the media plays a significant role in influencing people's decisions and shaping public opinion. While this power can be used for positive purposes, such as raising awareness about important issues, it can also be wielded in harmful ways that undermine democracy and promote consumerism. As individuals, it is important to critically evaluate the information we consume and consider the motivations behind media messages in order to make informed decisions. Ultimately, being aware of the media's influence can help us navigate the modern world with greater clarity and autonomy.。

Media Bias Assignment

Media Bias AssignmentI have posted a discussion of media bias below. In ityou will see a variety of factors which may beused to discern media bias. For this assignment you will write a paper of approximately 1000words. You should pick two separate newsarticles which discuss a single issue or event.Your paper should analyze the bias which maybe evident in one or both of the articles. You may choose articles which discuss any topic that you wish. You may choose an article which youbelieve demonstrates an anti-China bias, an anti-western bias, or any other bias which you wish to discuss. You may select any news publicationthat you wish. The paper will be due later in the semester. You should also submit copies of thearticles that you discuss.Media Bias AssignmentDetecting Media Bias &Propaganda “Nothing could be more irrational than togive the people power and to withhold from them information, without which power isabused. A people who mean to be their own governors must arm themselves with thepower which knowledge gives. A populargovernment without popular information or the means of acquiring it is but a prologue to a farce or a tragedy, or perhaps both.” -----James Madison----Democracy can be an effective form of government only to theextent that the public is well-informed about national and international events and can think independently and critically about those events. If the vast majority of citizens do not recognize bias in their nation’s news; if they cannot detect ideology slant, and spin, if they cannot recognize propaganda when exposed to it, they cannot reasonably determine what media messages have to be supplemented, counter-balanced, or thrown out entirely.On the one hand, world-wide news sources are increasingly sophisticated in media logic (the art of “persuading” and manipulating large masses of people). This enables them to create an aura of objectivity and “truthfulness” in the news stories they construct. On the other hand, only a small minority of citizens are skilled in recognizing bias and propaganda in the news disseminated in their country. Only a relatively few are able to detect one-sided portrayals of events or seek out alternative sources of information and opinion to compare to those of their mainstream news media.At present, the overwhelming majority of people in the world, untrained in critical thinking, are at the mercy of the news media in their own country. Their view of the world, which countries they identifyas friends and which as enemies, is determined largely by those media (and the traditional beliefs and conventions of theirsociety). This slanted information is not always a “plot” or a “conspiracy.” It is simply a matter of educational background and economic reality. Journalists and news editors are themselves members of a culture (German, French, Mexican, Chinese, Korean, Japanese, Indonesian, Russian, Algerian, Nigerian, North American, etc.). They share a view of the world with their target audience. They share a nationalized sense of history and allegiance, often a religion, and a general belief-system. An Arab editor sees the world different from an Israeli one. A Pakistani editor sees the world different from an Indian one. A Chinese editor sees the world different from an American one. The same is true of news reporters and other journalists.What is more, news people work under severe time restrictions (in constructing their stories) and limitations of space (in laying out or presenting their stories). It is hardly surprising that profound differences are reflected in news coverage from nation to nation and culture to culture. In any case, only those who understand the conditions under which world media operate have a chance of controlling the influence of their national media upon them. Our goal in this publication is to help our readers lay a foundation for transforming the influence of the media on their lives. It is in all of our interests to critically assess, rather thanmindlessly accept, news mediapronouncements.Media Bias AssignmentMedia / Political BiasNo matter how objective someone is,personal beliefs can influence their choiceof words. No matter how much we may tryto ignore it, human communication alwaystakes place in a context, through a medium, and among individuals and groups who are situated historically, politically,economically, and socially. This state ofaffairs is neither bad nor good. It simply is.Bias is a small word that identifies thecollective influences of the entire context ofa message. Therefore, bias may beintentional or unintentional. However, it isimportant to remember that the existence of bias does not necessarily mean that anarticle is false or unfair.Critical Questions For Detecting Bias1. What is the writer’s socio-political position?With what social, political, or professionalgroups is the writer identified?2. Does the writer have anything to gainpersonally from delivering the message inthe article?3. In what publication (newpaper, magazine,trade journal, etc.) does the articleappear? Does the publication have abias? Who stands to gain from thearticle?4. How does the writer present arguments? Is themessage one-sided, or does it includealternative points of view? Does the writerfairly present alternative arguments? Doesthe writer ignore obviously conflictingarguments?5. If the message includes alternative points ofview, how are those views characterized?Does the writer use positive words andimages to describe his/her point of view andnegative words and images to describe otherpoints of view? Does the writer ascribepositive motivations to his/her point of viewand negative motivations to alternativepoints of view?6. What sources does the writer use, andhow credible are they? Reporters oftenchoose sources that they know supporttheir view. Does the writer presentsources with contrary viewpoints?Media bias is present when a reporterpicks an “expert” source that supportsthe writer’s particular view of an issue.7. Does the writer cite statistics? Who gatheredthe data? How was the data gathered? Is thedata being presented fully? Were the peoplewho gathered the data biased?8. Check if important facts are omitted. Mediabias can be reflected in the absence of thewhole truth in a story.9. Pay attention to which stories are reported andwhich stories are ignored. Media bias can bereflected through an absence of coverage ofimportant or noteworthy events.10. Analyze the labels that are attached to certaingroups. Media bias can very easily depict anindividual or group of individuals in anymanner they like. Some groups are oftenreferred to as extreme, but others aredescribed as moderate. Media bias can veryeasily depict an individual or group ofindividuals in any manner they like.Propaganda:Propaganda is a systematic propagation of a doctrine, ideology, or idea of value to thespeaker. The key word in that definition is"systematic." Merely stating an ideology ordoctrine does not constitute propaganda. Theideology or doctrine must be spread through asystem of communication events with the long-term goal of getting the audience to adopt a newway of thinking.The term is often usedpejoratively to describe attempts to move publicopinion in a way, or to a position, that the criticdoesn't like. One person's propaganda isanother's cogent discourse. We should, however, put a finer point on the definition. We mayevaluate a messages as propaganda when wedetect that the speaker is trying to deceive morethan to persuade (understanding that this, too, isa judgment call)..One of the ways propagandamay be identified is through the systematic use of these common fallacies:1. Ad Hominem:This is argument "against the person,"also known as "name-calling." Thisfallacy signals propaganda when it isused to label people in order to boxthem off into categories. For example,always using the adjective "arch"before the noun "conservative" is oftena sign of a systematic intent tostereotype the individual so described.2. Either/or:This is the fallacy that there are onlytwo positions in a given argument oronly two approaches to a givensituation. Life is more complicated thansuch simplistic dichotomies lead us tobelieve.3. Ad Populum:This is argument "to the people," inwhich the speaker appeals to massemotions. This fallacy often requiresthe use of generalized or abstract termsthat have more emotional appeal thansubstance, e.g. patriotism, socialism,motherhood, radical, public-spirited. Arelated fallacy is called the"bandwagon," in which the speakerappeals to the audience's desire to bepart of a particular group.4. Transference:The speaker uses the thoughts of avenerable or symbolic figure to bolstera contemporary position, e.g. claimingthat George Washington would haveapproved of5. Stacking the Deck:One stacks the deck when he/sheleaves out relevant information, tellshalf-truths, exaggerates, or otherwisetampers with the facts. We often seethis technique used in the presenting ofstatistics and polling results.6. Opinion as Fact:The danger of stating opinion as fact ismost acute when the propagandist ismaking a report of an observed eventand using adjectives or adverbs to spinthe observations, e.g. "The candidatespoke convincingly about his tax program."。

bias指标的神奇用法

bias指标的神奇用法
Bias指标有很多神奇的用法，以下是其中一些主要用法：
1. 新闻媒体评估：将bias指标应用于新闻报道中可以帮助读者了解该报道的客观性和立场。

通过分析媒体的bias指标，读者可以更好地辨别报道中的潜在倾向和偏见。

2. 数据分析：在统计学和数据分析领域中，bias指标被用来评估样本选择的偏倚问题。

例如，如果一个样本中的个体不是随机选择的，那么可能会导致结果的偏离真实情况。

通过使用bias指标，可以识别并纠正这种偏差，以获得更准确的结果。

3. 机器学习模型评估：在机器学习中，bias指标被用来评估模型的偏差。

偏差是指模型对训练数据的拟合程度，如果模型的偏差很高，说明模型无法很好地拟合训练数据，可能存在欠拟合问题。

通过分析bias指标，可以调整模型的参数和结构，以降低偏差，提高模型的性能。

4. 客观性评估：在一些争议性话题上，bias指标被用来评估不同观点的客观性。

通过分析bias指标，可以了解不同观点的立场和偏见，从而更好地理解和评估这些观点。

总而言之，bias指标可以帮助我们识别和纠正偏见和偏差，提高决策的准确性和客观性。

无论是在新闻报道、数据分析、机器学习还是其他领域，bias指标都具有重要的应用价值。

让数字说话摘抄

让数字说话摘抄Title: Let the Numbers Speak数字是客观存在的，它们不会说谎，也不会有任何感情色彩。

然而，当我们把数字运用到各种领域时，它们就仿佛有了生命，可以为我们提供有价值的信息和洞见。

umbers are objective and do not lie.They carry no emotional bias.However, when we apply numbers to various fields, they seem to come alive, providing us with valuable information and insights.在商业领域，数字可以帮助我们了解市场趋势，预测未来发展方向。

比如，一家公司可以通过分析销售数据，了解消费者喜好，从而调整产品策略。

In the business world, numbers can help us understand market trends and predict future developments.For example, a company can analyze sales data to understand consumer preferences and adjust product strategies accordingly.在科研领域，数字是真理的化身。

科学家们通过实验得到一系列数据，然后通过分析这些数据，得出科学结论。

In scientific research, numbers embody the truth.Scientists obtain a series of data through experiments and then draw scientific conclusions by analyzing these data.在体育领域，数字可以帮助教练和球员更好地了解比赛情况，优化战术安排。

“平均数”的陷阱

“平均数”的陷阱不管是学过统计的还是没有学过统计的人，对于“平均数”这个概念想必不会陌生，但是，“平均数”真的是一个很容易理解和应用的概念吗？事实上，并非如此的简单，我们经常掉入“人为设计”的统计陷阱中而不能看到事实的真相。

“平均数”这个词有很广泛的含义。

当一个家伙希望影响公共概念时，或者向其他人推销广告版面时，平均数便是一个经常被使用的诡计，有时出于无心，但更多时候是明知故犯。

在统计上，平均数有三个具体的种类，分别是：均值（mean）、中位数（median）和众数（mode）。

其含义分别是：均值（Arithmetic mean，简称为mean）：是将一组数据的总和除以数据个数得到的，因此，一组数据只有一个均值，其计算公式如下：中位数（median）：英文解释是：a median is described as the number separating the higher half of a sample, a population, or a probability distribution, from the lower half. 是将所有数据按照由小到大进行排列，若数据为奇数个，中位数为中间那个数据；若数据为偶数个，中位数则是中间两个数的平均值。

众数（mode）：英文解释是：the value that has the largest number of observations。

是指一组数据中，出现频次最高的那个数据。

一组数据可以有多个众数，也可以没有众数。

三个平均数的关系是怎样的呢？这根数据的分布情况有关。

当数据的分布十分接近于正态分布时，它的均值、中位数和众数落在同一点上。

当数据的分布偏离正态分布时，数据的分布不再对称，而是有偏的，形状类似于孩子玩的滑梯，这时三个平均数就存在着较大的差异。

说到这里，相比大家已经很清楚这三个数据之间的差异。

一个没有加以限定的“平均数”，最终是没有意义的。

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Click here for quick links to Annual Reviews content online, including:• Other articles in this volume • Top cited articles• Top downloaded articles • Our comprehensive searchFurtherANNUAL REVIEWSIt’s no surprise to anyone who pays attention that mainstream media tilt their coverage in favor of Democrats and leftish ideas.But it’s not conﬁned to endless puff pieces about the president,or the ignoring of unpleasant facts.Often,it’s more subtle—as when the general thrust of a news story advances a particular narrative even when the facts within the story don’t really support it.For that sort of thing,you have to go to the acknowledged experts,the reporters and editors of The New York Times.Reynolds (2012)[T]he story here isn’t that Fox News leans right.Everyone knows the channel pushes a conservative-friendly version of the news.Everyone who’s been paying attention has known that since the channel’s inception more than a decade ago.The real story,and the real danger posed by the cable outlet,is that over time Fox News stopped simply leaning to the right and instead became an open and active political player,sort of one-part character assassin and one-part propagandist,depending on which party was in power.And that the operation thrives on fabrications and falsehoods.Boehlert (2011)The notion of a neutral “mainstream”national media gained a dominant following only in World War II and in its aftermath,when what turned out to be a temporary moderate consensus came to govern the country.Still,the notion of a neutral,nonpartisan mainstream press was,to me at least,worth holding onto.Now it’s pretty much dead,at least as the public sees things.Fineman (2005)INTRODUCTIONAre the news media politically biased?The question is simple to pose but surprisingly difﬁcult to answer.Or at least,difﬁcult to answer well.There is certainly no shortage of opinions on the subject.Books (mostly from ﬁgures outside of academia)purporting to answer the question have repeatedly shot to the top of the bestseller lists.1Networks of online media watchdogs and websites have sprung up to scour each day’s news content for errors,slights,or other malfeasance and trumpet their ﬁndings (Figure 1).Viewers of basic cable comedy shows like The Daily Show or The Colbert Report can count on a regular dose of media criticism along with their fake news.And of course,accusations of media bias were a go-to line for politicians (particularly on the right)even before Vice President Spiro Agnew complained of the “nattering nabobs of negativity”in the media.In the 2012election cycle,Republican presidential candidate Mitt Romney indicated that he “didn’t expect a fair ﬁght in the media,saying he believed most commentators on television were liberals”(Murray 2012).Even the most powerful man in the world has dabbled in media criticism;President Obama remarked in a 2010interview on the “tradition in this country of a press that oftentimes is opinionated.The golden age of an objective press was a pretty narrow span of time in our history.Before that,you had folks like Hearst who used their newspapers very intentionally to promote their viewpoints.I think Fox is part of that tradition—it is part of the tradition that has a very clear,undeniable point of view.It’s a point of view that I disagree with.It’s a point of view that I think is ultimately destructive for the long-term growth of a country that has a vibrant middle class and is competitive in the world”(Wenner 2010).21Two of the most successful of these books were Bernard Goldberg’s Bias:A CBS Insider Exposes How the Media Distort the News (2001)and Al Franken’s Lies and the Lying Liars Who Tell Them:A Fair and Balanced Look at the Right (2003),which each spent several weeks at the top of the New York Times nonﬁction bestseller lists.Both books present primarily anecdotal evidence and include chapter titles like “How About a Media that Reﬂects America,”“Paul Gigot is Unable to Defend an Incredibly Stupid Wall Street Journal Editorial,”“Where Thieves and Pimps Run Free,”and “Bill O’Reilly:Lying,Splotchy Bully.”Matching the chapters to their respective authors is left as an exercise for the reader.2Although his ﬂagship news network’s slogan is “Fair and Balanced,”Fox Chairman and CEO Rupert Murdoch has personally tended to have a very clear point of view in politics.For example,after the Romney campaign responded negatively to criticism130GroelingA n n u . R e v . P o l i t . S c i . 2013.16:129-151. D o w n l o a d e d f r o m w w w .a n n u a l r e v i e w s .o r g b y P e k i n g U n i v e r s i t y o n 11/18/13. F o r p e r s o n a l u s e o n l y .Figure 1Is media criticism a growth industry?Faith in the fairness and accuracy of the news media has also dropped precipitously among regular citizens.According to Pew (2011),whereas a clear majority (55%)of Americans trusted the news media to “get their facts straight”in 1985,only one in four Americans feel the same way now.Similarly,in 1985,34%of Americans trusted news organizations to deal fairly with all sides in “presenting the news dealing with political and social issues,”but less than half that percentage (16%)trusted them to do the same in 2011(see Figure 2).According to the same July 2011poll,nearly two-thirds of respondents agreed that news organizations were “politically biased in their reporting”(versus 45%in 1985).The public might largely have made up its mind,but the scholarly community is still very much undecided on the question of whether partisan bias in the news media truly exists.More to the point of this article,there is still a great deal of uncertainty about how to best approach answering the question empirically.of the candidate in Murdoch’s Twitter account,he somewhat defensively tweeted,“Romney people upset at me!Of course I want him to win,save us from socialism,etc.but should listen to good advice and get stuck in!”(Murdoch 2012). •Media Bias by the Numbers131A n n u . 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F o r p e r s o n a l u s e o n l y .OTHER DEFINITIONS OF BIAS:Noun “2.a particular tendency or inclination,especially one that prevents unprejudiced consideration of a question;prejudice.”Noun “3.Statistics:a systematic as opposed to a random distortion of a statistic as a result of sampling procedure.”Verb “9.to cause partiality or favoritism in (a person);inﬂuence,especially unfairly.”Stevenson et al.(1973):“...we decided to conceptualize bias as imbalance or inequality of coverage rather than as a departure from truth.While the latter deﬁnition can be used in some circumstances,it did not seem possible or useful to try to develop a ‘true’picture of the campaign to compare with CBS’version.”(p.213)Waldman &Devitt (1998):“Bias can be deﬁned as any systematic slant favoring one candidate or ideology over another.”(p.302)Gentzkow &Shapiro (2006):“All the accounts are based on the same set of underlying facts.Yet by selective omission,choice of words,and varying credibility ascribed to the primary source,each conveys a radically different impression of what actually happened.The choice to slant information in this way is what we will mean in this paper by media bias.”(p.281)Entman (2007):Content bias is deﬁned as “consistent patterns in the framing of mediated communication that promote the inﬂuence of one side in conﬂicts over the use of government power.”(p.166)systems on the texts they produce”(Entman 2010).3However,as I argue below,even if an individual or a news organization favors one partisan entity over another in their political view,the existence of a political opinion is neither necessary nor sufﬁcient to justify the conclusion that the news they produce would be biased.Instead,in order to effectively test for the presence of bias in the news,it seems clear that one must somehow examine the characteristics of that news.(See sidebar,“Other Deﬁnitions of Bias.”)In this analysis,I deﬁne media bias as a portrayal of reality that is signiﬁcantly and systematically (not randomly)distorted.Under this general deﬁnition,there are countless dimensions along which one might test for media bias,including portrayals of race,geography,class,etc.However,for purposes of this investigation,I limit the analysis to the subset of media bias that is chieﬂy concerned with relative treatment of American political parties:thus,I deﬁne partisan media bias as a signiﬁcantly distorted portrayal of reality that systematically and disproportionately favors one party over the other.Note that this deﬁnition requires that the researcher establish that any bias in coverage is systematic,rather than anecdotal,episodic,or ﬂeeting.4It also requires that the portrayal in the news be distorted in its portrayal of reality in some signiﬁcant way.Finally,it requires that the distortion favor one of the parties over the other.News coverage can become distorted through two main categories of choices by newsmakers:which events or information to cover,and how to cover them.I refer to systematically distorted decisions in these areas as selection bias and presentation bias,respectively (also see sidebar,“D’Alessio &Allen’s Typology of Media Bias”).3For studies of the characteristics and ideologies of American journalists,see Shaw (1985),Lichter et al.(1986),Weaver &Wilhoit (1991,1996,2007),Pew (2004,2005),and Cohen (2010).4Media criticism of the sort that appears on watchdog websites and popular outlets like The Daily Show is—almost by deﬁnition—episodic and anecdotal.Such analyses seem to be using the legal doctrine of falsus in uno,falsus in omnibus ,which holds that “a witness who willfully falsiﬁes one matter is not credible on any matter”(http://deﬁ/f/falsus-in-uno-falsus-in-omnibus/). •Media Bias by the Numbers133A n n u . 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F o r p e r s o n a l u s e o n l y .D’ALESSIO &ALLEN’S TYPOLOGY OF MEDIA BIASIn an inﬂuential review of the campaign media bias literature,D’Alessio &Allen (2000)present a helpful typology of media bias.They deﬁne and analyze gatekeeping bias (“the preference for selecting stories from one party or the other”);coverage bias,which “considers the relative amounts of coverage each party receives;”and statement bias,“which focuses on the favorability of coverage toward one party or the other”(p.133).Their concepts map closely to the ones put forth here,but were chosen to describe methodological approaches in (and limitations of)the existing literature rather than to distinguish categories of choices by news producers.For example,their conception of gatekeeping bias is explicitly limited to “stories that were picked up by media outlets in the ﬁrst place”and wonder,“What of stories that remained unreported?Is there bias,not in the selection of stories,but in the rejection of stories?”(p.150).The broader use of “selection bias”here is intended to capture such decisions more cleanly.Similarly,coverage bias explicitly assumes that a 50–50split in coverage between the parties constitutes fair coverage,which seems “impossible to measure”outside electoral politics,as the authors note (p.136).And ﬁnally,statement bias seems to exclude other methods of tilting story content—framing,visuals,issue focus,etc.Selection BiasNews organizations never have the time,personnel,funding,or bandwidth necessary to present all possible stories and must therefore choose to cover a subset of possible stories.As Hamilton (2006)has observed,the choice of what information will be selected to be marketed as news is perhaps the single most fundamental decision in journalism.Much like the problem of selection bias or biased sampling in statistics or survey research,selection bias occurs when not all units in the target population are equally likely to be included,either because they are not sought out by news organizations or are not published when available.As Groeling &Kernell (1998)note,if “news gatherers systematically draw an unrepresentative sample from the population of ...[possible]news stories,this practice alone might sufﬁce to skew ...coverage”(p.1,067).(See sidebar,“Gatekeeping in Action.”)Building on my deﬁnition of partisan media bias,the deﬁnition of partisan selection bias is choosing news stories that present a signiﬁcantly distorted sample of reality that systematically and disproportionately favors one party over the other.Presentation BiasWhereas selection bias skews the choices of what events or information to cover,presentation bias skews the content of those resulting stories.Presentation bias is the focus of the vast majority of the media bias literature.5As discussed below,scholars have analyzed the content of stories across a dizzying array of dimensions,including the sources present,tone,framing,issues,visual dimension,length,ordering,etc.I deﬁne partisan presentation bias as composing news stories in a manner that presents a signiﬁcantly distorted view of reality,which systematically and disproportionately favors one party over the other.Examples of Selection and Presentation BiasTable 1helps explain these concepts using hypothetical examples.Assume there are two news-worthy events,Events 1and 2,originating in Congress on a given day.For now,let us set aside5Some story elements might themselves be analyzable as a form of selection bias,such as when a show selects one source to appear in a story but not others.134GroelingA n n u . 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F o r p e r s o n a l u s e o n l y .GATEKEEPING IN ACTION“Politics is one area frequently dominated by the publisher’s policy,therefore by our deﬁnition,staffers observe this policy.And observe it they did—with a few interesting exceptions.In one case,a staffer ...substituting as wire editor on the latter’s night off omitted a story about a political sacred cow of the paper.The staffer never again was given this once-a-week job (which was considered a plum,bearing promise of advancement).That a publisher maintains his policy when he wants to is also shown in this story,told by an ‘insider’in a city where the chain paper in question is published:‘Mac is political editor [of the chain paper].Now his boss is committed to the ...[political]gang in town.Mac is supposed to go along.But we’re watching his stuff pretty carefully.We pretty soon get the hunch that old Mac is getting cute—not giving us a break at all.He doesn’t play up our boys any more than he does the others.Some pal.So Clarence,one of the boys,starts keeping a scrapbook on all of Mac’s stuff.He gets a bookful (sic)after about three-four months,and sends it along to —[the regional chain publisher].That took care of Mac.(What happened?)You should have seen the change.The very next day,Mac is phoning around,making dates for interviews with the boys.He even went up to Congressman A.’s house,the following morning before breakfast,so as to be sure and have something in that day’s paper.He’s been on the ball ever since.”(Breed 1952,pp.350–51)the issue of what constitutes newsworthiness and assume 1is more newsworthy and 2is less so.In the example,each event is also assumed to beneﬁt one party or the other some arbitrary amount if reported accurately.For this example,Event 1is assumed to strongly beneﬁt Democrats and harm Republicans;Event 2is equivalently beneﬁcial to both parties.If we are considering these two events to be the only two available partisan stories for the day (the “full population”),this appears to have been a good day for Democrats,since the most newsworthy event strongly beneﬁts them and harms Republicans,and neither event harms them.Table 1Story criteria and examplesPartisan beneﬁts of two eventsFavors whichparty?Population of possible storiesEvent #1:More important.Awful for Republicans (R),great for Democrats (D)Event #2:Lessimportant.OK for R,OK for DDCriterion?Resulting storyA.“Structural”(nonpartisan)selection bias#1:Awful for R,great for DD B.Pro-R partisan selection bias#2:OK for R,OK for DNeutral C.Pro-D partisan selection bias#1:Awful for R,great for D D D.Pro-R partisan presentation bias #1:Awful for R,OK for D D E.Severe pro-R partisan presentation bias #1:Great for R,awful for D R F.Pro-D presentation bias#1:Awful for R,great for DD •Media Bias by the Numbers 135A n n u . 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F o r p e r s o n a l u s e o n l y .If a news organization chose to report the full population of newsworthy events,it would present stories about both events,giving the Democrats better coverage overall than Republicans.However,as noted above,no news organization can devote the resources necessary to cover every single potential story,so the remaining rows of Table 1offer some criteria through which we might analyze those choices.Beginning with Row A,if we assume only the single most newsworthy story will be cho-sen by the news organization,it should choose to cover Event 1.Note that choosing only the most newsworthy stories is itself a form of selection bias (less newsworthy events are sys-tematically excluded from the sample),but not partisan selection bias.Hofstetter (1976)re-ferred to this as structural bias,in which “some things are selected to be reported rather than other things because of the character of the medium or because of the incentives that apply to commercial news programming instead of partisan prejudices held by newsmen”(p.34).Note,however,that the choice shown in Row A might lead to allegations of pro-Democratic bias on the part of the news organization.Because Event 1is much more favorable for Democrats than the ignored event,such charges would have face validity,since the story that could be shown would be unrepresentative of the events occurring that day in a way that beneﬁted a particular political party.Kuklinski &Sigelman (1992)discuss a similar problem,noting that changes in the political environment can systematically increase the newsworthiness of one party over another and produce news that favors one party over the other through objective news gathering and selection (the “paradox of objectivity”).However,because the choices would be proportionate to each party’s underlying newsworthiness,this type of selection bias would still not qualify as partisan selection bias.The next two rows of Table 1consider instances of partisan selection bias that favor Re-publicans (Row B)and Democrats (Row C),respectively.In Row B,the pro-Republican news organization has chosen to ignore Event 1,the more newsworthy event,in favor of one that bene-ﬁts both parties equivalently.It is important to note that researchers examining the story for signs of partisan presentation bias would ﬁnd none,as the story does not misrepresent the event in any way,and the two parties are treated equivalently in its content.Nonetheless,the choice to select this story over the more newsworthy option has the effect of changing a bad day for Republicans into one that beneﬁts neither party.In contrast,if a news organization were to favor Democrats over Republicans in its choices of what events to cover (Row C),it would choose Event 1,making it indistinguishable from an organization using more objective,structural story criteria,at least in this day’s coverage.These examples highlight how vital it is for media bias researchers to have some understanding of the underlying population of possible stories,which could then be used to evaluate the choices of news organizations.In all the cases discussed so far,news organizations differ in what events they have chosen to cover,but they accurately present information about the chosen events.In the next two hypothet-icals,we consider situations where a news organization has chosen to cover the more newsworthy event but has skewed its story in a way that favors Republicans.In the case of pro-Republican partisan presentation bias (Row D in Table 1),the story about Event 1is “spun”in such a way as to reduce the value of the story for Democrats while still accurately conveying its harmful im-plications for Republicans.Even though the story still favors Democrats overall,its presentation has diminished the degree to which the story beneﬁts them and is thus an example of partisan presentation bias.Next,Row E takes up a more severe case of pro-Republican partisan presentation bias.In this case,the news organization is still choosing to report the most newsworthy story of the day but136GroelingA n n u . 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F o r p e r s o n a l u s e o n l y .does so in a way that fundamentally misrepresents the event,changing it from one that strongly favors Democrats to one that strongly beneﬁts Republicans.Finally,in Row F,we examine how a pro-Democratic news organization might present the news of the day.As we saw in Row C,such efforts might actually be indistinguishable from scrupulously neutral reporting,since the most newsworthy event is already massively beneﬁcial to Democrats and damaging to their opponents,so all that is necessary to beneﬁt Democrats is to accurately report it.Table 1highlights some of the difﬁculties researchers face in trying to empirically test for media bias.Even in a simpliﬁed hypothetical case where we know the “true”newsworthiness and partisan impact of stories,it is sometimes difﬁcult to distinguish between news choices that are nonpartisan and those that favor a party (note that the predicted stories generated by nonpartisan and pro-Democratic journalists are equivalent here in rows A,C,and F).And as I discuss in the next section,real-world empirical research into media bias faces far more severe challenges than this simple hypothetical.CHALLENGES FACING RESEARCHERS TESTING FOR MEDIA BIASBeyond mundane problems such as securing access to news content,the difﬁculty and expense of mounting a major content analysis,and getting such research placed in top journals,researchers face two main challenges:the unobserved population problem and subjectivity.The Problem of the Unobserved PopulationWhen faced with allegations of media bias,journalists and news organizations often defend them-selves by arguing that their coverage was a fair representation of reality and that the accuser is just unhappy about the true state of the world.[As comedian Stephen Colbert (2006)sarcasti-cally put it,“reality has a well-known liberal bias.”]Longtime CBS Evening News anchor Walter Cronkite famously said,“Our job is only to hold up the mirror—to tell and show the public what has happened.Then it is the job of the people to decide whether they have faith in their leaders or governments”(quoted in Alan &Lane 2003,pp.139–40).As it turns out,the “mirror”claim is actually quite difﬁcult to address empirically.In most cases,only the news organizations that assembled the stories are aware of the potential stories that were not selected for distribution.Outside observers—especially prior to the advent of new media—could only view the ﬁnal product of the newsgathering process;any “raw material”that ended up on the cutting-room ﬂoor was part of an unobserved population.Table 2sets out another hypothetical example of news content to help illustrate this point.Here we see a week’s worth of news from a hypothetical news provider presented in a format similar to Table 1.A cursory glance at Table 2would suggest that coverage favored the Democrats (ﬁve days’coverage favored them,one favored Republicans,and one was neutral).However,the researcher would have no idea from what “true”population of news these stories were selected,so there would be no way to tell whether the selection of these stories exhibited partisan bias.As Groeling &Kernell (1998,p.1,067)put it,“research based exclusively on content analysis of reported news commits the fallacy of drawing inferences from data that has been selected on the dependent variable.The issue of selection bias presents this research with a serious conundrum.How can it assess the representativeness of the sample when the population is comprised mostly of stories that were never reported and thereby elude observation?”D’Alessio &Allen (2000)made a similar point when they pessimistically concluded that such biases might be unknowable.“If one considers the universe of all stories as a population and the •Media Bias by the Numbers137A n n u . 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F o r p e r s o n a l u s e o n l y .Table 2Unobserved population example:week of news from hypothetical news organizationPartisan impactFavors which party?Population of possible stories???Day Story presentedDay 1Neutral for R,neutral for D Neutral Day 2OK for R,awful for D R Day 3Awful for R,OK for D D Day 4Awful for R,great for D D Day 5Bad for R,neutral for D D Day 6Neutral for R,great for D D Day 7Awful for R,OK for DDAbbreviations:R,Republicans;D,Democrats.list of those that are covered as a sample,the presumption is that,because the ‘sampling’procedure is carried out by individuals with opinions,the selection therefore will be biased.This is only a presumption,however,as the ‘population’is not only unknowable but unidentiﬁable.What would be ‘all the news in the world?’And,in the absence of population data,although it is safe to presume that gatekeeping bias occurs,it is impossible to know,or even estimate,its magnitude”(p.136).Not knowing the objective underlying characteristics of the events selected for coverage also undermines the ability of researchers to assess partisan presentation bias.In much of the literature on media bias,researchers have “solved”this problem by assuming that the parties are equivalently advantaged and that truly unbiased coverage should be “balanced.”And in fact,there are contexts in which this assumption might be more justiﬁed than others.As D’Alessio &Allen (2000)suggest,“...a two-party system,which produces two essentially qualiﬁed candidates,each campaigning at roughly the same level,should produce events,activities,and discussion in two roughly equal amounts.Thus,coverage should be roughly equal for each side,and any departure from a ‘50–50’split could be considered a consequence of some kind of bias”(p.137).Studies covering much longer historical time frames,which might be expected to cover a broader range of institutional and situational variation,might also be expected to be reasonably balanced.However,as Schiffer (2006)notes,“deviation from the balance baseline that results from non-partisan,non-ideological aspects of the newsmaking process will spuriously appear as partisan slant....At ﬁrst glance,this problem appears intractable.After all,if balance fails as a suitable baseline,then how does one calculate an expected coverage premium for a given reality condi-tion?...[T]he lack of a feasible solution makes the balance baseline no less problematic”(p.24;see also Niven 2003on this point).And Druckman &Parkin (2005)provide a baleful summary of the issue,concluding that “one of the prime lessons of research on media slant or bias concerns the futility of searching for an ‘objective’standard by which to assess bias.These studies suggest that the most effective strategy is to instead focus on relative comparisons of coverage”(p.1,031).The Subjectivity ProblemThe problem of subjectivity and its consequences are comparatively well known,especially to researchers who must train human coders to reliably and uniformly conduct content analyses.Perhaps the most famous example of such subjectivity is the “hostile media”phenomenon,in which identical stories were perceived as having diametrically opposed biases depending on who viewed them (Vallone et al.1985).138GroelingA n n u . 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