Practical Findings from Applying the PSD Model for Evaluating Software Design Specifications

1. Teppo Räisänen | University of Oulu Practical Findings from Applying the PSD Model for Evaluating Software Design Specifications Teppo Räisänen Tuomas Lehto Harri Oinas-Kukkonen University of Oulu, Finland

2. Teppo Räisänen | University of Oulu Outline • Background • Requirements engineering • Case • Results • ELM and PSD

3. Teppo Räisänen | University of Oulu Outline • Background • Requirements engineering • Case • Results • ELM and PSD THIS IS AN ACTUAL PRESENTATION I GAVE IN PERSUASIVE 2010 CONFERENCE IN COPENHAGEN, DENMARK

4. Teppo Räisänen | University of Oulu Background • We have applied the PSD model in a similar fashion for a half a dozen traditional persuasive cases • Alcohol, weight-loss, exercise behaviors • Research collaboration with an Oulu-based technology company who have been developing a reference platform for mobile Internet device • = a mobile device that can be used to design mobile devices • Cf. Google’s Android or Nokia’s Symbian • In this paper • Analysing the software requirements in the design specification documents

5. Teppo Räisänen | University of Oulu Background

6. Teppo Räisänen | University of Oulu Background • Any changes inthe SW are moreexpensivethe later in theprocess they areintroduced

7. Teppo Räisänen | University of Oulu Background In addition to this, behavior andattitude change shouldbe taken into accountearly in the designprocess

8. Teppo Räisänen | University of Oulu Requirements engineering • Early part of the software system development process • ”Branch of software engineering concerned with the real-world goals for, functions of, and constraints on software systems. It is also concerned with the relationship of these factors to precise specifications of software behavior, and to their evolution over time and across software families.” [1]

9. Teppo Räisänen | University of Oulu Requirements engineering • Eliciting requirements • Modeling and analyzing requirements • Communicating requirements • Agreeing requirements, and • Evolving requirements

10. Teppo Räisänen | University of Oulu Requirements engineering • Communicating requirements • Communication with stakeholders • Agreeing requirements • Establishing a consensus that the requirements and models elicited provide an accurate account of what the stakeholders want • Evolving requirements • Handling changes in the requirement documents

11. Teppo Räisänen | University of Oulu Requirements engineering • Eliciting requirements • Identify all the stakeholders (e.g. customers, developers, users) • Identify the objectives and tasks of the system • Prototyping, brainstorming, focus groups • Modeling and analyzing requirements • Produce abstract descriptions of the requirements so that they would be amenable to interpretation. • Data modeling, domain modeling, behavior modeling • If we design persuasive systems domain modeling and behavior modeling are crucial

12. Teppo Räisänen | University of Oulu Requirements engineering • Domain modeling helps understand the persuasion context • PSD: The intent, the event, and the strategy • Behavior modeling helps identify opportunities for different behavior change types • Potentially even Kairos • Microsuasion vs macrosuasion

13. Teppo Räisänen | University of Oulu Case • We utilized the PSD Model to evaluate requirements specifications of a mobile Internet device • We received many requirements documents related mainly to user interface and user interaction issues • They were full of live-sized pictures, descriptions of the touchpad gestures, and user interface elements

14. Teppo Räisänen | University of Oulu Case

15. Teppo Räisänen | University of Oulu Case • Two researchers independently evaluated the documents through the PSD framework • A joint understanding was formed through face-to-face discussion • All persuasive principles from the PSD Model were considered and the SW was graded in terms how well the requirements seemed to support them • The company was then provided with the results and a list of suggestions on how to improve the persuasiveness and usability of the system

16. Teppo Räisänen | University of Oulu Results • The case demonstrated that the PSD Model works well for evaluating SW requirement • It was somewhat difficult to identify the primary task of the case system • Mobile phone, Internet device, social networking • It was little bit of a challenge to analyze primary task issues

17. Teppo Räisänen | University of Oulu Results • The case also demonstrated how various PSD principles work together • Many times pairing PSD principles has good synergy • Suggestion-reward • Suggestion-personalization • Self-monitoring-reminders • Similarity-liking • Competition-cooperation • Simulation-rehearsal

18. Teppo Räisänen | University of Oulu Results • Sometimes principles do not complement each other • Abundant use of reduction makes tunneling nearly irrelevant • Rather than trying to utilize all principles, a coherent set of features should be applied • Emphasizing synergy

19. Teppo Räisänen | University of Oulu Results • Another challenge was that some of the PSD model’s social support principles are highly interlinked with each other • Social learning vs social comparison • Some aspects are difficult to evaluate at specification level • Credibility support • No explicit evaluation heuristics have been defined yet • Without heuristics the evaluation is more subjective

20. Teppo Räisänen | University of Oulu Theories and PSD • PSD Model is a meta-level model • Practitioners can utilize the model and gain benefits from it • Researchers still need a theoretical framework to gain full benefits of the model • Some suitable theories • Elaboration Likelihood Model (ELM) • Theory of Reasoned Action (TRA) • Theory of Planned Behavior (TPB) • Social Cognitive Theory (SCT)

21. Teppo Räisänen | University of Oulu Elaboration Likelihood Model (ELM)

22. Teppo Räisänen | University of Oulu Elaboration Likelihood Model (ELM) Look at the yes arrows in the model above

23. Teppo Räisänen | University of Oulu Elaboration Likelihood Model (ELM) PSD can support most of them

24. Teppo Räisänen | University of Oulu ELM and PSD Dialogue support

25. Teppo Räisänen | University of Oulu ELM and PSD Social support Dialogue support

26. Teppo Räisänen | University of Oulu ELM and PSD Primary task support Social support Dialogue support

27. Teppo Räisänen | University of Oulu ELM and PSD Primary task support Credibility support Social support Dialogue support

28. Teppo Räisänen | University of Oulu Conclusion • PSD Model can be used to evaluation purposes • It could benefit from specific heuristics • Persuasive principles used in design should be selected so that they have increased synergy when utilized together • By using the PSD Model together with suitable behavior and attitude change theories we can achieve better results

29. Teppo Räisänen | University of Oulu Questions? Teppo.raisanen@oulu.fi THANK YOU!