准确度(Accuracy)与精密度(Precision)的区别

准确度(Accuracy)与精密度(Precision)的区别

In the fields of?engineering,?industry?and?statistics, the?accuracy?of

a?measurement?system is the degree of closeness of measurements of a quantity?to its actual (true)?value. The?precision?of a measurement system, also

called?reproducibility?or?repeatability, is the degree to which repeated measurements under unchanged conditions show the same?results.[1]?Although the two words can

be?synonymous?in?colloquial?use, they are deliberately contrasted in the context of the?scientific method.

Accuracy准确度 is the difference between the measured value and the true value of a tested material.

Precision精确度 is the repeatability of successive measurements under the same conditions.

测量的精密度、准确度和精确度

这是人们在测量中常常容易混淆的三个名词，虽然它们都是评价测量结果好坏的，但涵义有较大的差别。

1．测量的精密度高，是指偶然误差较小，这时测量数据比较集中，但系统误差的大小并不明确。

2．测量的准确度高，是指系统误差较小，这时测量数据的平均值偏离真值较少，但数据分散的情况，即偶然误差的大小不明确。

3．测量精确度（也常简称精度）高，是指偶然误差与系统误差都比较小，这时测量数据比较集中在真值附近。

Accuracy?

Accuracy is?how close a measured value is to the actual (true) value.? Precision?

Precision is?how close the measured values are to each other.?

准确度（Accuracy）：指在一定实验条件下多次测定的平均值与真值相符合的程度，以误差来表示。它用来表示系统误差的大小。

精密度（Precision）：是指多次重复测定同一量时各测定值之间彼此相符合的程度。表征测定过程中随机误差的大小。

（精密度高是指重复性好repeatability，描述仪器本身的性能用precision；最对比实验得到的结果用准确度accuracy，对比仪器的值可看作真值；一般实验结果给出的是标准偏差standard deviation，用不确定度uncertainty表示）

精确度=准确度+精密度?

可用下图表示：

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Accuracy and precision in binary classification?

"Accuracy" is also used as a statistical measure of how well a binary classification test correctly identifies or excludes a condition.? That is,?the accuracy is the?proportion?of true results (both true positives and true negatives) in the population. It is a parameter of the test?

On the other hand, precision is defined as?the proportion of the true positives against all the positive results (both true positives and false positives)