1. Information System Design Info-440
Autumn 2002
Session #2

2. Agenda Admin: Assignments & deliverable guidelines registration
Norman’s design vocabulary
Assignment #1
Break
Mental and conceptual models
Norman’s model of interaction: Seven stages of interaction
Copyright David Hendry (INFO-440 session /02/2002)

3. Quick review Definitions Gatorade bottle case
Design Method
Usability: Learnability, Efficiency, etc.
Gatorade bottle case
Small, near transparent, details matter a lot
Challenge to look beyond the surface
Designing a mere bottle is very complicated
Quick overview of syllabus – Questions?
Copyright David Hendry (INFO-440 session /02/2002)

4. Admin: Deliverable guidelines
Standard cover sheet
Standard formatting
Grading guidelines
Late policy
Re-grading policy
Academic honesty
*See website for details
Copyright David Hendry (INFO-440 session /02/2002)

5. Assignments Design exercises (4 assignments)
Studying artifacts
Organize facts and deriving concepts (group)
Conceptual modeling & system specification
Usability assessment
Interactive prototype project
Four intermediate deliverables during quarter
Final deliverable: 13 December
Copyright David Hendry (INFO-440 session /02/2002)

6. Assignments (cont.) Weekly quizzes Participation 20min Short answers
Ask questions, give answers
Show work, accept criticism
Develop an on-line journal (Catalyst Portfolio)
Post to discussion board
Copyright David Hendry (INFO-440 session /02/2002)

7. Norman’s design vocabulary

8. Affordances Will the ball roll? Yes! But, how do you know?
Copyright David Hendry (INFO-440 session /02/2002)

9. Affordances
Objects have certain natural tendencies (push, pull, roll, etc.)
Which of these doors can you pull?
Copyright David Hendry (INFO-440 session /02/2002)

10. My Watch What do the buttons do?
Copyright David Hendry (INFO-440 session /02/2002)

11. My Watch Lots of functions Timer Calendar Alarm Stop watch
Copyright David Hendry (INFO-440 session /02/2002)

12. My Watch Goal: Does this watch have a light? Its not easy to decide.
Copyright David Hendry (INFO-440 session /02/2002)

13. Using Norman’s vocabulary
The watch light has no visibility
It’s hidden at the edge of the watch
No mapping between button and function
Nothing indicates which button is for the light
The feedback from the buttons is very subtle and confusing
Display changes, sound, light mine if there is a light
The mode button has an affordance (appropriate cue) but it is fairly weak
Copyright David Hendry (INFO-440 session /02/2002)

14. Key terms from Norman’s Chapter
Afforance
Natural mappings
Feedback
Constraint
Visibility
Copyright David Hendry (INFO-440 session /02/2002)

15. Criticizing designs A key problem: Language poverty Solution:
Examples: user friendly, intuitive, natural, consistent..
Different people, interpret concepts differently
Solution:
Language that identifies common problems
More rigorous meanings
Open to non-specialists (everyone)
Norman’s language is a superb contribution
Copyright David Hendry (INFO-440 session /02/2002)

16. Design Exercise #1

17. Part I Identify a breakdown in the world Document it
Spend time observing people
Look for interesting interactions
Document it
Explain it with Norman’s vocabulary
Propose a solution
Copyright David Hendry (INFO-440 session /02/2002)

18. My bad day at the gas pump
Copyright David Hendry (INFO-440 session /02/2002)

19. Part II Select a scene where an object is being used by a person
Boring example: Lance Armstrong drinking from Gatorade bottle
Describe
Person and object
Tasks that can be carried out with object
New features (you invent them)
Copyright David Hendry (INFO-440 session /02/2002)

20. Deliverable A presentation (powerpoint) Audience Seven slides
Your peers
Assume informal presentation
Seven slides
Say only what is important
Simple, direct presentation
Copyright David Hendry (INFO-440 session /02/2002)

21. Conceptual Models

22. Definitions Conceptual model
An account of the entities and relationships in a system
Copyright David Hendry (INFO-440 session /02/2002)

23. Nuclear power plan (normal)
Relief value
Pressurizer
Level
Reactor
Liquid water
Pump
Vincent, K. (1999). Cognitive Work Analysis. New York: Lawrence Erlbaum Associates.
Copyright David Hendry (INFO-440 session /02/2002)

24. Nuclear power plan (abnormal)
Relief value
Pressurizer
Level (high)
Reactor
Liquid water
Steam
Pump
Copyright David Hendry (INFO-440 session /02/2002)

25. Definitions Mental model User model vs. design model
The knowledge of a system within a person’s head
You can elicit a mental model from a user
User model vs. design model
Designers usually have different mental models than users
Copyright David Hendry (INFO-440 session /02/2002)

26. Models: Others are possible
Document: Conceptual model
DESIGNER: Design Model
USER: User Model
System: System Image
PLUS manual
watch
Copyright David Hendry (INFO-440 session /02/2002)

27. Summary Know the differences between:
Conceptual model
Mental model
User model
Design model
System image
More on Conceptual models in Week #4
See Benyon, Green & Bental (1999)
Copyright David Hendry (INFO-440 session /02/2002)

28. Next time Work on Read Next week Design Exercise #1 (Due: 9 Oct)
Beyer & Holtzblatt, chapter #3
Interactive prototyping project
Next week
Requirements analysis
Copyright David Hendry (INFO-440 session /02/2002)