Comprehending Object and Process Models An Empiric

This particular study
▪ Compares OO and PO models based on: ▪ Comprehension involving:
1. Only structural aspects 2. Only behavioral (process-oriented) aspects 3. Both
“We must consider the larger development picture, which encompasses organizational and social, as well as technological factors.” - D.E. Perry
Similarities
▪ OO lends itself naturally to the way humans think.
▪ However:
▪ Evidence from research suggest that human problem solving is innately procedural.
Research
Additional comments
▪ Subjects were undergrad students studying information systems from a large state university
▪ Most likely had prior knowledge of PO models, but were trained in OO modeling.
ቤተ መጻሕፍቲ ባይዱut…
▪ Both OO and PO provide techniques to model info processing systems
▪ However the approach in each model is different
Differences
▪ Hence their respective names:
▪ Prior research shows:
▪ An individual’s ability to effectively use a certain method is factored by:
▪ the nature of the application being modeled ▪ the type of prior modeling experience
▪ During the initial phases of development, both models developed are abstract, focusing on the external qualities of the system.
▪ They both become more and more detailed as they progress, as implementation-related factors are taken into account.
Experiment 2 (Texas Case)
Experiment 2
Experiment 2
Experiment 2
Statistics
Statistics
Statistics
Results
▪ For ‘complex’ questions, PO had better accuracy than OO.
Keep in Mind
▪ PO may have been easier because of its age and prior knowledge.
Conclusion
▪ Although both PO and OO models are informationally equivalent, the study shows that a PO model is computationally more efficient, but only for complex questions.
▪ To guard against bias, same instructor was used to refresh PO knowledge and teach OO.
Experiment 1 (ABC Case)
Experiment 1
Experiment 1
Experiment 1
How to decide which is better?
▪ Previous studies have failed to factor the ease of understanding the models:
▪ Effective communication is possible only when the models themselves are completely comprehensible.
Object Oriented Models (cont.)
▪ Major Advantage:
Provides continuum of representation from analysis to design to implementation.
▪ However:
Though there are many technical advantages, problems with OO are not technical.
▪ Comprehension was measured from subjects’ responses to questions designed from above points.
Environment of test
▪ Two experiments were conducted
▪ Each with different applications and different groups of subjects.
Results
▪ From the experiment, PO seemed easier to comprehend since most questions could be answered by looking at only graphical representation, while OO needed both graphical and technical descriptions.
▪ Strong Indications that PO models are easier to comprehend that OO for more complex questions
▪ Complex meaning involving both structure and process-oriented aspects.
▪ Each subject was trained in both methods, participated in one of the two experiments, then answered questions relating to his/her comprehension of OO or PO.
▪ Process Oriented Models are built around processes (and behavior).
▪ Object Oriented Models are built around objects (and structure).
Arguments
▪ There have been many arguments that OO is more powerful:
▪ If looking at the efficiency of a model by comprehension, PO seems to be the more logical choice.
谢谢
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Object Oriented Models
▪ Fairly newer, becoming more popular ▪ Benefits include:
▪ Encapsulation (info hiding) ▪ Polymorphism ▪ Inheritance ▪ Reusability