How can we ensure the usability improves with the next generation of AT products

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How can we ensure the usability improves with the
next generation of AT products

• Sean Loughran
• sloughran_at_enableireland.ie

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DX Rem55 controller
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Content

• Analyse the current design
• Proposal for a redesign
• Key findings from research

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Analyse the current design

• Cognitive Process and relevant cognitive theories
  
• Input and outputs of the interface
• The interaction style
• Its success for targeted user groups

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Cognitive Process and Relevant cognitive theories
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Perception

• User may have a difficulty with seeing the screen
  (2 ¼ inch)
• No auditory feedback
• Tactile feedback from the buttons on the
  controller and on the Joystick itself

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Affordance
The psychological idea of affordance says that
things may suggest by their shape and other
attributes what you can do with them.
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Gestalt psychology Objects near each other tend
to be grouped together
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Visual entities must be close together in order
for them to be perceptually grouped.
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Metaphors used

• The controller has five profiles. In general the
  higher the profile numbers the greater the max
  speed
• Deflection of the joystick is proportional to the
  speed of the chair
• An arc is displayed with its length directly
  proportional to the speed
• All are metaphors, mirroring the controls in most
  vehicles eg the gear stick with 5 gears, the
  accelerator pedal and the speedometer

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Input and outputs of the system
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Inputs
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Output

• Screen
• Tactile feedback from button and Joystick
• Kinesthetic feedback

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Interaction style
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Success of joystick for targeted user groups

• Input and outputs are appropriate for the user
• Good metaphors chosen
• Objects on the screen are too small
• Button position is poor
• Inconsistency of joystick operation and
  inconsistency of symbols in menu making the
  system difficult to learn

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Proposal for a redesign

• Usability Engineering lifecycle model
• Prototyping
• Design rules
• Cognitive Walkthrough and a Heuristic evaluation

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Usability Engineering lifecycle model

• A set of usability activities that are performed
  at different stages of the lifecycle of a product
  
• One should not rush into the design
• Usability activities include visits to user sites
  to get to know the user, prototyping, heuristic
  evaluation

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Prototypes low fidelity
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Prototypes high fidelity
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Design rules

• Smith and Mosier (1986)
• Seven Principles of Universal Design

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Evaluation Methods

• Heuristic evaluation
• Look at the interface and see what is good or bad
  in relation to a set of usability principles or
  guidelines.
• Cognitive Walkthrough

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Proposal for redesign of interface

• Keypad buttons need to be closer to the area that
  represents their function on the LCD display
• Move the On/Off and the Indicator buttons closer
  to the joystick
• Replaced accessory buttons with a single
  accessory button
• Consistency in joystick operation.
• Consistency in symbols used within menu

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Proposal for redesign of interface
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Key findings from research

• Most usability activities are straight forward to
  implement.
• Users can point out usability issues that you
  cannot see.
• Usability issues are not always immediately
  obvious.

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Conclusion

• Ideally have a systematic approach to usability
• Devote time and resources to usability
• We may all have some influence on future product
  design.

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Bibliography

• Dix, A., Finlay, J. Abowd, G.D., 2004.
  Human-computer interaction, Pearson Education.
• Nielsen, J., 1993. Usability engineering, Morgan
  Kaufmann.
• Shneiderman, B. Plaisant, C., 2010. Designing
  the user interface strategies for effective
  human-computer interaction, Addison-Wesley.