Knowledge in the head and world
SYS 214 - Principles of HCI
agenda
- Notes
- Research due next week's Sunday (Oct 11)
- Read the deliverable list
- Start working on Analysis (Oct 18)
- Wednesday - bring camera!
- Next Friday - Share your first draft of your "As is model" in class
- Research due next week's Sunday (Oct 11)
- Prep for Monday
- Zoom out to the big picture
- Discussion and Wrap-up
- Exercise
prep for monday
DWMIM Chapters 7, 8, 9
big picture
What are the HCI Principles supposed to help us do?
big picture
What are the HCI Principles supposed to help us do?
- COMMUNICATE how to interact
Interaction
| Gulf of Execution | ||
 |
 |
|
| Gulf of Evaluation |
Seven stages of action
- Form the goal
- Form the intention
- Specify the action
- Act
- Perceive the state
- Interpret the state
- Evaluate the outcome
Discussion
“"Precision, accuracy, and completeness of knowledge are seldom required." (p.55)
”
How does this chapter coach us on communicating the correct action to end users?
Constraints
What does a constraint do for us?
Physical Constraints
Physical Constraints
Physical Constraints
Cultural constraints and conventions
Cultural constraints and conventions
Cultural constraints and conventions
Discussion
What are some examples of constraints in interface design?
Knowledge in the head/body
- Knowledge "of"
- Facts
- Knowledge "how" (tacit knowledge)
- Examples
- Typing
- Riding a bike
- Designing process
- Learn through demonstration and practice
- Sub-conscious
- Examples
Knowledge in the world
Knowledge in the world
knowledge
Property: Learning
- Knowledge in the World
- Learning not required. Interpretation substitutes for learning. How easy it is to interpret information in the world depends upon how well it exploits natural mappings and constraints.
- Knowledge in the Head
- Requires learning, which can be considerable. Learning is made easier if there is meaning of structure to the material (or if there is a good mental model).
knowledge
Property: Efficiency of Use
- Knowledge in the World
- Tends to be slowed up by the need to find and interpret the external information.
- Knowledge in the Head
- Can be very efficient
knowledge
Property: Efficiency of Use
- Knowledge in the World
- High
- Knowledge in the Head
- Low
User
Communicate correct choice of action =
+ 
+ Constraints
Constraints
Constraints limit choices
Constraints
How are constraints used here?
Challenges
What is the challenge here?
Natural mappings
reminders
application summary
- Use constraints and knowledge in the head or knowledge in the world to eliminate the need to remember exact instructions.
- When using knowledge in the world, ensure that the knowledge is easy to translate.
- When requiring knowledge in the head, be cognizant of how much you are asking users to remember and take advantage of meaningful structure like mental models.
- Use natural mappings.
- When using reminders, think about the message and the signal.
Interaction review
In groups of two, choose a web site or app that you can access now. (no game apps please)
Exercise: You are an interaction design team. A client has asked you to review their web site.
- Using the principles discussed in class/reading to date, evaluate the web site (use your books and notes!)
- What principles are used well?
- Name the principle and tell why it is done well.
- What principles are not used well?
- Name the principle and tell why it is not used well.
- What principles are used well?
Be prepared to present your evaluation to the class.
