Comprehending Object Comprehending Object and Process Models:and Process Models:An Empirical StudyAn Empirical Study

Aritcle by: Ritu Agarwal, Prabuddha De, and Atish P. SinhaAritcle by: Ritu Agarwal, Prabuddha De, and Atish P. Sinha

Analysis by: Jerome TunayaAnalysis by: Jerome Tunaya

IntroductionIntroduction

Many systems development methods, Many systems development methods, dominant ones include:dominant ones include:

Process Oriented ModelsProcess Oriented Models

Object Oriented ModelsObject Oriented Models

Process Oriented ModelsProcess Oriented Models

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

Object Oriented ModelsObject Oriented Models

Fairly newer, becoming more popularFairly newer, becoming more popular Benefits include:Benefits include:

Encapsulation (info hiding)Encapsulation (info hiding) PolymorphismPolymorphism InheritanceInheritance ReusabilityReusability

Object Oriented Models (cont.)Object Oriented Models (cont.)

Major Advantage: Major Advantage: Provides continuum of representation from analysis to design to Provides continuum of representation from analysis to design to implementation.implementation.

However:However:Though there are many technical advantages, problems with OO Though there are many technical advantages, problems with OO are not technical.are not technical.

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

SimilaritiesSimilarities During the initial phases of development, During the initial phases of development,

both models developed are abstract, both models developed are abstract, focusing on the external qualities of the focusing on the external qualities of the system.system.

They both become more and more They both become more and more detailed as they progress, as detailed as they progress, as implementation-related factors are taken implementation-related factors are taken into account.into account.

But…But… Both OO and PO provide techniques to Both OO and PO provide techniques to

model info processing systemsmodel info processing systems However the approach in each model is However the approach in each model is

differentdifferent

DifferencesDifferences Hence their respective names:Hence their respective names:

Process Oriented Models are built around Process Oriented Models are built around processes (and behavior).processes (and behavior).

Object Oriented Models are built around Object Oriented Models are built around objects (and structure).objects (and structure).

ArgumentsArguments There have been many arguments that There have been many arguments that

OO is more powerful:OO is more powerful: OO lends itself naturally to the way humans OO lends itself naturally to the way humans

think.think. However:However:

Evidence from research suggest that human Evidence from research suggest that human problem solving is innately procedural.problem solving is innately procedural.

ResearchResearch Prior research shows:Prior research shows:

An individual’s ability to effectively use a An individual’s ability to effectively use a certain method is factored by:certain method is factored by: the nature of the application being modeled the nature of the application being modeled the type of prior modeling experiencethe type of prior modeling experience

How to decide which is How to decide which is better?better?

Previous studies have failed to factor the Previous studies have failed to factor the ease of understanding the models:ease of understanding the models: Effective communication is possible only Effective communication is possible only

when the models themselves are completely when the models themselves are completely comprehensible.comprehensible.

This particular studyThis particular study Compares OO and PO models based on:Compares OO and PO models based on:

Comprehension involving:Comprehension involving:1.1. Only structural aspectsOnly structural aspects2.2. Only behavioral (process-oriented) aspectsOnly behavioral (process-oriented) aspects3.3. BothBoth

Comprehension was measured from Comprehension was measured from subjects’ responses to questions designed subjects’ responses to questions designed from above points.from above points.

Environment of testEnvironment of test Two experiments were conductedTwo experiments were conducted

Each with different applications and different Each with different applications and different groups of subjects.groups of subjects. Each subject was trained in both methods, Each subject was trained in both methods,

participated in one of the two experiments, then participated in one of the two experiments, then answered questions relating to his/her answered questions relating to his/her comprehension of OO or PO.comprehension of OO or PO.

Additional commentsAdditional comments Subjects were undergrad students Subjects were undergrad students

studying information systems from a studying information systems from a large state universitylarge state university Most likely had prior knowledge of PO Most likely had prior knowledge of PO

models, but were trained in OO modeling.models, but were trained in OO modeling. To guard against bias, same instructor was To guard against bias, same instructor was

used to refresh PO knowledge and teach used to refresh PO knowledge and teach OO.OO.

Experiment 1 (ABC Case)Experiment 1 (ABC Case)

Experiment Experiment 11

Experiment 1Experiment 1

Experiment 1Experiment 1

Experiment 2 (Texas Case)Experiment 2 (Texas Case)

Experiment 2Experiment 2

Experiment 2Experiment 2

Experiment 2Experiment 2

StatisticsStatistics

StatisticsStatistics

StatisticsStatistics

ResultsResults For ‘complex’ questions, PO had better For ‘complex’ questions, PO had better

accuracy than OO.accuracy than OO. Strong Indications that PO models are Strong Indications that PO models are

easier to comprehend that OO for more easier to comprehend that OO for more complex questionscomplex questions

Complex meaning involving both structure Complex meaning involving both structure and process-oriented aspects.and process-oriented aspects.

ResultsResults From the experiment, PO seemed easier From the experiment, PO seemed easier

to comprehend since most questions to comprehend since most questions could be answered by looking at only could be answered by looking at only graphical representation, while OO graphical representation, while OO needed both graphical and technical needed both graphical and technical descriptions.descriptions.

Keep in MindKeep in Mind PO may have been easier because of its PO may have been easier because of its

age and prior knowledge.age and prior knowledge.

ConclusionConclusion Although both PO and OO models are Although both PO and OO models are

informationally equivalent, the study informationally equivalent, the study shows that a PO model is shows that a PO model is computationally more efficient, but only computationally more efficient, but only for complex questions.for complex questions.

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