Comprehending Object and Process Models: An Empirical Study

Comprehending Object and Process Models:An Empirical Study Aritcle by: Ritu Agarwal, Prabuddha De, and Atish P. Sinha Analysis by: Jerome Tunaya

Introduction • Many systems development methods, dominant ones include: • Process Oriented Models • Object Oriented Models

Process Oriented Models • Has dominated systems development efforts for over thirty years, especially those that deal largely with structured techniques.

Object Oriented Models • Fairly newer, becoming more popular • Benefits include: • Encapsulation (info hiding) • Polymorphism • Inheritance • Reusability

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. “We must consider the larger development picture, which encompasses organizational and social, as well as technological factors.” - D.E. Perry

Similarities • 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.

But… • Both OO and PO provide techniques to model info processing systems • However the approach in each model is different

Differences • Hence their respective names: • 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: • OO lends itself naturally to the way humans think. • However: • Evidence from research suggest that human problem solving is innately procedural.

Research • 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

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.

This particular study • Compares OO and PO models based on: • Comprehension involving: • Only structural aspects • Only behavioral (process-oriented) aspects • Both • 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. • 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.

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. • To guard against bias, same instructor was used to refresh PO knowledge and teach OO.

Experiment 1 (ABC Case)

Experiment 1

Experiment 2 (Texas Case)

Experiment 2

Statistics

Results • For ‘complex’ questions, PO had better accuracy than OO. • Strong Indications that PO models are easier to comprehend that OO for more complex questions • Complex meaning involving both structure and process-oriented aspects.

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.

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. • If looking at the efficiency of a model by comprehension, PO seems to be the more logical choice.

Comprehending Object and Process Models: An Empirical Study