1. Answering Why and Why Not Questions in User Interfaces
Brad Myers, David A. Weitzman, Andrew J. Ko, and Duen Horng Chau
Presented By: Craig Prince and Alan Liu
CSE590H Autumn 2007

2. Brad Myers 1987 – Ph.D. from U. of Toronto
1987 to 1995 – (Senior) Research CMU-CS
1995 to present – Senior Research Scientist, Associate Research Professor, and CMU-HCII
Some Research Interests:
End-User/Natural Programming and PBD
Handheld Interfaces
Quality of Life Technology
User Interface Design Tools

3. Answering Why and Why Not…
Contributions:
Interaction Design
Implementation Framework
Gulf of Evaluation
Interpreting what one sees on the screen and fix it if it’s not what the user intended
Complementary to Gulf of Execution?

4. Why and Why Not…based on Command History

5. Why or Why Not…based on Selected Object

6. Answer to Why or Why Not

7. Implementation Command-Object Model (Crystal)
Commands are used for Undo and Why/Why Not questions
Commands know their dependent properties
Commands know the controls which change them

8. Designer’s Role
Have to design your application to follow a command-object model
Designer needs to pick out level of granularity
Needs to determine when to include “why not” questions
10% more code?

9. User Study: Example Task
1. Type in the following sentence “The abbreviation fl. oz. stands for fluid ounce.”
2. You notice that the word processor has capitalized some characters for you, but you don’t want this to happen.
3. Your task is to make the automatic capitalization not happen again.
4. When you think you’re done, type “fl. oz. stands” again to make sure it works.

10. Results

11. Discussion 1
What types of applications do you think this would work well for? Which would it not?
Is it just bad design to not make it obvious why things happen?
This system requires an application to be designed explicitly to use it, how does this effect it’s adoption?

12. Discussion 2
Was their user study well designed? How does their system compare to traditional help systems?
Do you think their tasks were realistic?
Did the user study evaluate their design or their concept?

13. Discussion 3
Are “why” questions the most common types of questions? Do novice users ask “why” questions?
Does the shortcutting hinder learning of new features of an application? Shortcutting doesn’t bridge the gulf of execution.

14. Discussion 4
How could/would you use this system to explain more complex phenomenon? (E.g. “Why did the sharpen filter leave these visual artifacts?” or “Why didn’t the face detector detect that face?”)