Design of Everyday Things

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Design of Everyday Things

• Don Norman on Design HCI

This material has been developed by Georgia Tech
HCI faculty, and continues to evolve.
Contributors include Gregory Abowd, Jim Foley,
Diane Gromala, Elizabeth Mynatt, Jeff Pierce,
Colin Potts, Chris Shaw, John Stasko, and Bruce
Walker. Comments directed to foley_at_cc.gatech.edu
are encouraged. Permission is granted to use with
acknowledgement for non-profit purposes. Last
revision February 2004.
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Project Part 1 -- return

• General comments
• Be careful with generalizations and stereotypes
• Make sure you understand users goals
• Socio-technical environment
• Focus both users and usability criteria
• Report more details of evaluations

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Project Part 2

• Functional and Nonfunctional requirements
• Design space
• Details of least 3 prototypes, try and EXPLORE
  the design space
• Think different kinds of input, output, mobility,
  size, usability criteria, or aspects of the task
• At least one scenario of use, and assessment, for
  each prototype

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Poster Session

• Next Friday (June 11)
• Present brief description of the problem, and
  your prototypes
• Great chance for feedback!

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Summary
Darn these hooves! I hit the wrong switch
again! Who designs these instrument Panels,
raccoon?!
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Don Norman

• Professor at Northwestern and Principal of
  Nielsen Norman group
• Previously Professor at UCSD, senior positions at
  Apple HP
• ACM/CHI Lifetime Achievement Award
• Prolific author

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Discussion

• What did you take away from DOET book?
• Write down three key take-away messages

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Here are some

• Affordances are important
• Minimize the gulf of interpretation and gulf of
  execution
• Use natural mappings
• Make state visible
• Use a conceptual model that makes sense
• Provide feedback

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Daily Challenges

• How many of you can use all the functionality in
  your
• VCR
• Digital watch
• Copy machine
• Stereo system
• Plumbing fixtures

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Hall of Shame Example

• Leitz slide projector
• To move forward, short press
• To move backward, long press
• What happens when you get frustrated?

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Fun Examples
Phones
How do you - transfer a call - change volume -
store a number - ...
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(No Transcript)
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Changing Ringer Volume

• Press Program
• Press 6
• Set volume
• Low - Press 1
• Medium - Press 2
• High - Press 3
• Press Program

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Important Concepts

• Affordances
• Visibility
• Conceptual models
• Mapping
• Feedback
• Constraints

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Affordance

• What is it?

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Visual Affordances

• Perceived and actual properties of an object that
  determine how it could be used
• Chair is for sitting
• Button is for pushing
• Door handle is for .
• Scroll arrow is for
• Icon is for

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Door Opening Affordances
1
2
3
4
5

• Which doors are easy to open?
• Which doors are hard to open?
• Why?

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7
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Lack of Affordance Example
What in the world is this glass for?
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Now with an Affordance!!
This sure makes it obvious!
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Mantra

• 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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Designing for People

• Normans 2 main principles
• Provide a good conceptual model
• Make things visible
• Affordances is part of this

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Conceptual Model

• What does Norman mean by that?

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Conceptual Models

• People build their own systems of how things work
• Example - thermostat
• Designer can help user foster an appropriate
  conceptual model
• Appearance, instructions, behavior...

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Conceptual Models

• Mental models are not always right
• Two Classes
• Functional model
• Stimulus - response
• Press the accelerator once, then turn the key
• At surface or superficial level
• Structural model
• Deeper sense of why it happens, not just what
  happens
• Press the accelerator to engage the automatic
  choke on a carburetor

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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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Simple Example

• Bathroom faucets
• Two functions
• Hot/cold
• Flow

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Bathroom Faucets 1
Can you figure out how to use it? Are two
functions clear and independent?
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Bathroom Faucets 2
Can you figure out how to use it? Are two
functions clear and independent?
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Bathroom Faucets 3
Can you figure out how to use it? Are two
functions clear and independent?
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About that VCR

• That old joke - how many of you have a VCR that
  is blinking 1200? -)
• Still true today -(

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Which is Faster for Setting Time?
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Two Important Principles

• Mapping
• Feedback

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Mapping

• What does this mean?

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Mapping

• Relationship between control and action/result
• Good
• Car, various driving controls
• Mercedes Benz seat adjustment example
• Bad
• Car stereo - Knob for front/back speakers

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Mapping Example Euros

• Sizevalue

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Mapping Example Stove

• Which controls which?

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Yikes!
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Why Not Design Better

• Stove
• Speakers

Physical, monetary, convenience,
etc., constraints dictate otherwise
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Feedback

• Let someone know what just occurred
• Can be sound thats made
• Can be change in physical state

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Example
Scissors
Affordances - Insert something into
holes Constraints - Bigger hole for several
fingers, small for thumb Mapping - How to insert
fingers into holes suggested by
visible appearance Conceptual model - Suggested
by how parts fit together and move
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Execution-Evaluation cycle

• Norman (DOET, p. 46)

Gulf of Execution
User Goals
Physical System
Gulf of Evaluation
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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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Execution
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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Evaluation
Goals What we want to happen
Evaluation of the interpretations with what we
expected to happen
Interpreting the perception according to our
expectations
Perceiving the state of the world
Physical System
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Seven Stages - All Together
Goals What we want to happen
Evaluation of the interpretations with what we
expected to happen
An intention to act so as to achieve the goal
Interpreting the perception according to our
expectations
The actual sequence of actions that we plan to do
Perceiving the state of the world
The physical execution of that action sequence
Physical System
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Implications Which Gulf does Each of These
Address?

• Make current state and action alternatives
  visible
• Need good conceptual model with consistent system
  image
• Interface should include mappings that reveal
  relationships between stages
• User should receive continuous feedback
• Provide affordances

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Goal Minimize Gulfs

• Gulf of Execution
• Conceptual model
• Affordances
• Natural mappings

• Gulf of Interpretation
• Make state visible
• Feedback

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Why Design is Hard

• Number of things to control has increased
  dramatically
• Displays are more virtual/artificial
• Marketplace pressure
• Adding operations cheaper (computers)
• Adding controls expensive (real estate, cost)
• Errors are becoming increasingly serious

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Try and Try Again

• Norman thinks that it often takes 5 or 6 tries to
  get something right
• Simply may not have that luxury in a competitive
  business environment