The Psychology of Everyday Actions

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The Psychology of Everyday Actions
Shyh-Chii Tzeng (Sept. 26, 2007) Department of
Learning and Digital Technology Fo Guang
University
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• Why does an object keep on moving?
• Which path does the ball take?

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• Mental model, our conceptual models of the way
  objects work, events take place, or people
  behave, result from our tendency to form
  explanations of things.
• Mental models are often constructed from
  fragmentary evidence with but a poor
  understanding of what is happening, and with a
  kind of naïve psychology that postulate causes,
  mechanisms, and relationships even where there
  are none.

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• People tend to assign a causal relation whenever
  two things occur in succession.
• People tend to blame themselves for failure with
  everyday objects.
• It seems natural for people to blame their own
  misfortunes on the environment and to blame other
  peoples misfortunes on their personalities.

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Goals What we want to happen
Evaluation Comparing what happened with what we
wanted to happen
Execution What we do to the world
THE WORLD
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Goals
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
THE WORLD
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Goals
Evaluation of the interpretations with what we
expected to happen
Interpreting the perception according to our
expectations
Perceiving the state of the world
THE WORLD
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Goals
Evaluation of interpretations
Intention to act
Interpreting the perception
Sequence of actions
Perceiving the state of the world
Execution of the action sequence
THE WORLD
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• The gulf of execution the difference between the
  intentions and the allowable actions. One measure
  of the gulf is how well the system allows the
  person to do the intended actions directly,
  without extra effort.

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• The gulf of evaluation reflects the amount of
  effort that the person must exert to interpret
  the physical state of the system and to determine
  how well the expectations and intentions have
  been met. The gulf is small when the system
  provides information about its state in a form
  that is easy to get, is easy to interpret, and
  matches the way the person thinks of the system.

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How Easily Can One

• Determine The Function
• of the Device

• Tell What Actions Are Possible?
• Determine Mapping from Intention to Physical
  Movement?
• Perform the Action?

• Tell if System is in Desired State?
• Determine Mapping from System State to
  Interpretation?
• Tell What State the System is In?

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User-Centered Design
Shyh-Chii Tzeng (Sept. 26, 2007) Department of
Learning and Digital Technology Fo Guang
University
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• A philosophy based on the needs and interests of
  the user, with an emphasis on making products
  usable and understandable.

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• Design should
• Make it easy to determine what actions are
  possible at any moment (make use of constraints).
• Make things visible, including the conceptual
  model of the system, the alternative actions, and
  the results of actions.

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• Design should
• Make it easy to evaluate the current state of the
  system.
• Follow natural mappings between intentions and
  the required actions between actions and the
  resulting effect and between the information
  that is visible and the interpretation of the
  system state.

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• Use both knowledge in the world and knowledge in
  the head.
• Simplify the structure of tasks.
• Make things visible bridge the gulfs of
  execution and evaluation.
• Get the mapping right.
• Exploit the power of constraints, both natural
  and artificial.

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• Design for error.
• When all else fails, standardize.

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• Three conceptual models
• The roles of manuals

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• Be aware of the limitations of attention, short-
  and long-term memories.
• Use technology to make tasks simpler.

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• Four major technological approaches
• Keep the task much the same, but provide mental
  aids.
• Use technology to make visible what would
  otherwise be invisible, thus improving feedback
  and the ability to keep control.
• Automate, but keep the task much the same.
• Change the nature of the task.

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The design model is the designers conceptual
model. The users model is the mental model
developed through interaction with the systems.
The system image results from the physical
structure that has been built (including
documentation, instructions, and labels). The
design expects the users model to be identical
to the design model. But the designer doesnt
talk directly with the user-all communication
takes places through the system image. If the
system image does not make the design model clear
and consistent, then the user will end up with
the wrong mental model.
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• Let people know what is possible and how actions
  should be done by making things visible on the
  execution side of an action .
• Let people can tell the effects of their actions
  by making things visible on the evaluation side .

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• Make sure people can decide the relationships
  between
• intentions and possible actions
• actions and their effects on the system
• actual system state and what is perceivable by
  sight, sound, or feel
• the perceived system state and the needs,
  intentions, and expectations of the user

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• Use constraints so that the user feels as if
  there is only one possible thing to dothe right
  thing.

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• Try to support, not fight, the users responses.
  Allow the user to recover from errors, to know
  what was done and what happened, and to reverse
  any unwanted outcome.

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• Ex. typewriter, keyboards, traffic signs,
  symbols, units of measurement, calendars, etc.
• The timing of standardization is important.

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• Ex.
• Hide critical components make things invisible.
• Use unnatural mapping for the execution side of
  the action cycle so that the relationship of the
  controls to the things being controlled is
  inappropriate or haphazard.

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• Make the actions physically difficult to do.
• Require precise timing and physical manipulation.
• Do not give any feedback.
• Use unnatural mapping for the evaluation side of
  the action cycle so that system state is
  difficult to interpret.

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• Ex. Surfboard, ice skates, parallel bars, etc.
• Many simple devices is capable of a wide
  repertoire of actions with few controls.

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• Complexity of appearance seems to be determined
  by the number of controls, whereas difficulty of
  use is jointly determined by the number of
  finding the relevant controls and difficulty of
  executing the functions.
• How do we make things easy to use and look like
  they are easy?

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• Complexity of appearance seems to be determined
  by the number of controls, whereas difficulty of
  use is jointly determined by the number of
  finding the relevant controls and difficulty of
  executing the functions.
• How do we make things easy to use and look like
  they are easy?

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• ???????????
• ??Emotion design Attractive things work better
• Motivation principles

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References

• Norman, D. A. (2002). The design of everyday
  things. New York Basic Books.