Lecture

1

Lecture 1b Introduction to Interaction Design
2
Lecture Overview

• Part I Design Concepts
• Part II Group Artifact Analysis and Discussion

3
Part IDesign Concepts
4
Design Concepts

• Generalizable abstractions for thinking about
  different aspects of design
• Help determine what to provide and what not to
  provide at the interface
• Derived from a mix of theory-based knowledge,
  experience and common-sense
• Note often too general to be helpful

5
Fundamental Design Concepts

• Affordances
• Constraints
• Mappings
• Conceptual models
• Visibility
• Feedback
• Transfer effects
• Population stereotypes
• Individual differences

6
Affordances (Gibson)

• Perceived or actual properties of an object that
  determine how it could possibly be used
• Shows relationship between what you want to do
  and what is possible (Perceivable possibilities
  for action)
• Examples. . .

7
Affordance Doorknob
8
Affordance? Doorknob (2)
9
Affordance Chairs
10
Constraints

• Perceived limitations of the actions that are
  possible with an object
• Based on objects appearance
• Show what parts operate and how
• Suggest range of possible uses
• Helps prevent user from selecting incorrect
  options
• Three main types (Norman)
• physical
• cultural
• logical
• Examples. . .

11
Physical Constraints Light Switches
12
Logical Constraints? Labels on Back of Computer
13
Cultural Constraints

• Learned arbitrary conventions like red
  triangles for warning
• Can be universal or culturally specific

14
Mappings

• The set of possible relations between objects
• Physical mappings
• Displays and controls
• Cultural mappings
• Functionality and appearance
• Examples. . .

15
Mappings Fireplace Flue
16
Mappings Stove
A
B
C
D
17
Mappings Stove (2)
18
Conceptual Models

• Mental model of an object that consists of
• Parts
• Possible actions and effects
• When you have a conceptual model, you can perform
  a simplified mental simulation of how something
  works
• Examples. . .

19
Conceptual Model Dishwasher
20
Conceptual Model Thermostat
21
Visibility

• Make what can be done visible
• Visibility suffers when the number of possible
  actions exceeds the number of controls
• Examples. . .

22
Visibility Elevator

• This is a control panel for an elevator.
• How does it work?
• Push a button for the floor you want?
• Nothing happens. Push any other button? Still
  nothing. What do you need to do?
• What to do is not visible!

From www.baddesigns.com
23
Visibility Elevator (cont.)

• You need to insert your room card in the slot by
  the buttons to get the elevator to work!

24
Visibility Cell Phone
25
Feedback

• Sending information back to the user about what
  has been done
• Includes sound, tactile, and visual feedback
• e.g. when screen button clicked on provides sound
  or red highlight feedback

ccclichhk
26
Feedback Fireplace Flue
27
Feedback Copier
28
Transfer Effects

• Prior experience influences what functionality we
  expect for an object and how we operate an object
• Learning by analogy and metaphor
• Can be both positive and negative
• Positive This is a pair of scissors therefore,
  you put your fingers in the holes
• Negative This keyboard looks like a phone pad
  maybe I can use it to key in a phone number

29
Population Stereotypes

• Assumptions about a group of people who use an
  object
• Can be cultural and physical
• Examples
• In US, people expect light switch down to be
  off in UK down is on
• Everyones keyboard will have a function pad
• People understand concept of restart
• All keyboards have function keys

30
Individual Differences

• Individuals within a group differ by experience,
  interests, and ability
• Examples
• Some people are right-handed, others are left,
  and still others are ambidextrous
• I usually remember how to program my VCR
• I can never remember how to set my answering
  machine greeting.

31
Part II Group Activity

• Divide into groups of 5 to 6
• Each group will be given an artifact to evaluate
  with respect to the design concepts just
  introduced
• As a group, evaluate your artifact with respect
  to the design concepts just introduced (see next
  slide).
• Note both the positive and negative aspects of
  your artifacts design with respect to the design
  concepts. (Note that not all concepts may apply.)
• Have a scribe keep track of your discussion, and
  write down key points for possible presentation
• Near end of class, instructor may call on you to
  introduce your artifact and discuss your results.