Designing Everyday Things

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Designing Everyday Things

• 20,000 ??? !!!

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Agenda

• Questions
• Project parts 0 1
• Reactions to DOET 1-2
• Important concepts

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Project part 0

• Comments grades from the TA
• A few people did not do certificationdo it or
  your grades on later project parts will be
  affected
• No topic yet? Pick one!

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Project part 1

• Start working on it (due September 17)
• Short presentation (September 13)
• Know thy user
• Task analysis
• Larger system (there is always one)
• Usability criteria
• Techniques used
• Implications of what you learned

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Don Norman

• Northwestern University
• Nielsen Norman Group
• Formerly
• HP
• Apple
• UCSD
• ACM/CHI Lifetime Achievement Aware
• Writes a lot!

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Your thoughts

• Initial impressions

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Reflections

• Good examples
• Car
• VCR
• Watches
• Doors
• Relatively few computing examples

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Important concepts

• Natural mapping
• Visibility
• Perceived affordance
• Feedback
• Mental models / conceptual models
• 7 stages of action

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Mapping

• The relationship between two things
• Y F(X)
• Relationship between controls their movements
  and the results in the world

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Mapping
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Natural mapping
Why not?
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Visibility

• Make capabilities perceivable and interpretable
• Counteracting factors
• Features
• Aesthetics
• Abstractions

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Visibility

• Examples?

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Visibility

• When functionality is hidden, problems in use
  occur
• Occurs when number of functions is greater than
  number of controls
• When capabilities are visible, it does not
  require memory of how to use
• Recognition over recall
• In the world vs. in the head

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Feedback

• Sending back to the user information about what
  action has actually been done, what result has
  been accomplished
• i.e., let someone know what just occurred
• Can be sound thats made
• Can be change in physical state

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Affordance

• Perceived and actual properties of a thing
• Fundamental properties that determine just how a
  thing could possibly be used
• How does this apply to design?
• Complex things may need explanation, but simple
  things should not
• If a simple thing requires instructions, it is
  likely a failed design

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Affordance

• Chair provides support for holding something off
  of the ground
• Chair affords sitting
• Button affords pushing
• Door handle affords

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Lack of affordance
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Now with an affordance
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Too many affordances ?

• Different properties may afford different uses

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Conceptual models

• People build their own understanding of how
  things work
• But how? What factors contribute to a users
  conceptual model of a system?
• Visibility
• Affordances
• Constraints (e.g., scissors, floppy disk, keys)
• Mappings

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Conceptual models

• How do you think it works?
• Thermostat
• Walk button
• Mental models are not always right

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People are explanatory creatures

• User falsely blaming the wrong cause
• User falsely blaming oneself for errors

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Foster appropriate conceptual model

• How does the something actually work?
• How does the user think the thing works?
• How should the user conceptualize about (1)?

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Designing for people

• Provide clear mappings between controls and
  behaviors
• Make states possible actions/behaviors visible
• Afford the intended use
• Provide feedback of actions/behaviors
• Foster appropriate mental models
• Designers are not users

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Goals, execution, evaluation
Goals What we want to happen
Execution What we do to the world
Evaluation Comparing what happened with what we
wanted to happen
(Gulf of Execution)
(Gulf of Evaluation)
Physical System
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In more detail

• 7 stages of action

Goals What we want to happen
An intention to act so as to achieve the goal
The actual sequence of actions that we plan to do
The physical execution of that action sequence
Physical System
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Goal minimize gulfs

• Gulf of execution
• Conceptual Model
• Affordances
• Natural mappings

• Gulf of evaluation
• Make state visible
• Feedback