User-Centered Design

1. User-Centered Design HCI Design Process CS 4750 - Fall 2004

2. Agenda • Project part 0 • Quiz • Review (?) • What is user-centered design? • SE life cycles • Where do HCI techniques fit in? CS 4750 - Fall 2004

3. Project part 0 • Teams formed (?) • Turn in copy of IRB certification CS 4750 - Fall 2004

4. Quiz CS 4750 - Fall 2004

5. Designing effective UIs • It’s HARD!!! • Educate software professionals • Do NOT wait ‘til the end • Good UI can not be pasted on top of poorly-designed functionality • Draw upon accumulating body of knowledge regarding HCI interface design • Integrate UI design methods & techniques into standard software development methodologies now in place CS 4750 - Fall 2004

6. What is design? • “Achieving goals within constraints” -- DFAB • Design is driven by requirements CS 4750 - Fall 2004

7. Organizational & Social Issues Task Design Technology Humans What is design? CS 4750 - Fall 2004

8. Design Code Test Deployment & maintenance Traditional software lifecycle • Waterfall Requirements analysis CS 4750 - Fall 2004

9. Why waterfall fails • Difficult to determine all requirements from the start (batch fallacy) • Users may want to perform tasks that weren’t intended by the designer • Some tasks will only be known after the user has interacted with the system • Doesn’t support the user’s perspective of the system CS 4750 - Fall 2004

10. Design Code Test Deployment & maintenance Addressing “batch fallacy” problem • Waterfall Requirements analysis CS 4750 - Fall 2004

11. Spiral lifecycle model CS 4750 - Fall 2004 From cctr.umkc.edu/~kennethjuwng/spiral.htm

12. The solution • Building a system as a means of understanding requirements • Iteration • Prototyping • Incorporate evaluation • Formative • Summative • Involve the user • Under the user • Think of world in user’s terms • Develop with the target user CS 4750 - Fall 2004

13. Methods for applying HCI • Generative: strategies to build a better interface • Evaluative: assessing existing interface CS 4750 - Fall 2004

14. Generative techniques • Apply principles (upcoming lectures) • Chapter 7 • Build prototypes • Apply design rules (guidelines/standards) • Do usability specifications (see book) CS 4750 - Fall 2004

15. Ways of prototyping • Storyboards • Limited function • High-level languages CS 4750 - Fall 2004

16. The point behind prototyping… • Better understand user requirements through exposure to system • Not (necessarily) your final system • Fred Brooks’ rule for SE • Authenticity of prototype important CS 4750 - Fall 2004

17. Categories of prototypes • Throw-away • Incremental • Evolutionary CS 4750 - Fall 2004

18. Throw-away prototype • Design & build prototype • Test prototype & gain knowledge • Prototype is discarded • Knowledge is used for future iterations of design CS 4750 - Fall 2004

19. Incremental prototype • Prototype built as separate components • Product is released in a series • Each series contains a new component CS 4750 - Fall 2004

20. Evolutionary prototype • Prototype is built & tested • Prototype serves as the basis for the next iteration of design CS 4750 - Fall 2004

21. Design rules generic Guide line generality standards specific suggestion hard + fast rule authority CS 4750 - Fall 2004

22. Design rules examples • http://www.ida.liu.se/~miker/hci/guidelines.html CS 4750 - Fall 2004

23. Evaluative methods • Summative • Questionnaire design, interviews • User studies • Protocol analysis • Formative • Heuristic evaluation • Cognitive walkthrough • Cooperative evaluation, modelling CS 4750 - Fall 2004

24. Another distinction • Quantitative • Numerical evidence • Cause  effect hypothesis • Qualitative • Ethnography • Observations CS 4750 - Fall 2004

25. Know Thy Users! • Physical & cognitive abilities (& special needs) • Personality & culture • Knowledge & skills • Motivation • Two Fatal Mistakes: • Assume all users are alike • Assume all users are like the designer You Are Here CS 4750 - Fall 2004