1. Scenario-Based Usability Engineering Chris North cs3724: HCI

2. Homework #0: UI Analysis • See website • Pick a movie of your choice • Task: find a convenient playing time and location • Use 3 different systems: • 1-800-555-TELL • www.moviefone.com • www.hollywood.com/showtimes/ • Write down the time it takes you for each • Bring your times to class on Thursday

3. Homework #0 • Qualitative discussion • Usability problems, errors, access, alternate tasks, … • Quantitative discussion • Data averages, min, max • Data visualization • Statistics, t-tests, …

4. Myth • The user interface is tacked on at the end of the project

5. The Changing Face of Computer Use Professional programmers, “software psychology” 1960’s Business professionals, mainframes, command-line 1970’s Large, diverse user groups, “the computer for the rest of us” 1980’s World Wide Web and more, information access & overload 1990’s Ubiquitous computing, diversity in task, device, … 2000+

6. Newton vs. Palm • Newton • Palm

7. User Interface Metrics • Ease of learning • Ease of use • User satisfaction Not “user friendly”

8. Tradeoffs • Optimization? • Examples • Identify tradeoffs • Choose based on design goals • Track tradeoffs for rationale

9. Using “Scenarios” Stories about people and their needs, activities A problem scenario describing current situation: Marissa was not satisfied with her class today on gravitation and planetary motion. She is not certain whether smaller planets always move faster or how a larger or denser sun would alter the possibilities for solar systems. She stays after class to speak with Ms. Gould, but she isn’t able to pose these questions clearly, so Ms. Gould suggests that she re-read the text and promises more discussion tomorrow.

10. A design scenario describing our initial vision: Marissa , a 10th-grade physics student, is studying gravity and its role in planetary motion. She goes to the virtual science lab and navigates to the gravity room. In the gravity room, she discovers two other students, Randy and David, already working with the Alternate Reality Kit, which allows students to alter various physical parameters (such as the universal gravitational constant) and then observe effects in a simulation world. The three students, each of whom is from a different school in the county, discuss possible experiments by typing messages from their respective personal computers. Together they build and analyze several solar systems, eventually focusing on the question of how comets can disrupt otherwise stable systems. They capture data from their experiments and display it with several visualization tools, then write a brief report of their experiments, sending it for comments to Don, another student in Marissa’s class, and Mr. Arkins, Randy’s physics teacher.

11. Scenario Elements • Setting • Actors (people, users) • Task goals (what I want to achieve) • Plans (how I will accomplish it) • Actions (do it) • Events (system response) • Evaluation (is that what I wanted?)

12. Advantages of Scenarios

13. ANALYZE analysis of stakeholders, field studies claims about current practice Problem scenarios DESIGN Activity scenarios metaphors, information technology, HCI theory, guidelines iterative analysis of usability claims and re-design Information scenarios Interaction scenarios PROTOTYPE & EVALUATE summative evaluation formative evaluation Usability specifications

14. Iterative • Fuzzy -> clear

15. Iterative • Fuzzy -> clear

16. Iterative • Sometimes “design is radically transformational”

17. Summary • Measurable Metrics! • Tradeoffs • Scenarios, elements • Scenario-based UE process • Iterative • assignment: • Download & install java sdk1.4, Borland JBuilder • Read Ch 2

18. Presentations • Groups of 2 • 5 minutes, 2-3 slides • Pick UI of your choice (software or real-world) • UI critique • Scenarios/tasks • Good • Bad • Redesign ideas? • Vote: UI Hall of Fame/Shame

19. Fast Food Drive-Thru Menus • Scenarios: • College student • hungry • Get food, get out. FAST! • Often: sandwich, fries, drink • Typically: Not sure what I want • Sometimes: Know what I want • Passengers want food too • Limited budget

20. The Good • All in one view • Organized by categories • Tabular format: left alligned, prices alligned • Combo meals (high frequency) • Get price before proceeding • Some: feedback on order Need picture!

21. The Bad • See menu too late • Passengers cant see menu • Passengers must order thru driver • Winter: brrrrr… • Small Redesign ideas: • More menus back in line • Menu on both sides of car • Microphone on both sides • Radical: cell phone, in-car UI

22. The Ugly • I can’t understand a word they say • They cant hear me over my ’87 VW