Usability

1
Usability

• Jennifer Eley
• Mayumi Abe

2
The Definition of Usability

• The effectiveness, efficiency, and satisfaction
  with which users can achieve tasks in a
  particular environment of a product.
• A quality attribute that assesses how easy a user
  interface is to use.
• methods for improving ease-of-use during the
  design process.

3
Five Key Components

• Easy to learn.
• Efficient to learn.
• Easy to remember.
• Error prevention.
• Satisfying.

4
What Can We Do with Usability?

• Uncover the real needs and tasks of the user.
• Eliminate over-design.
• Provide data.
• Reduce costs.
• Provide a competitive advantage.
• Have a demonstrable effect deployment costs and
  user productivity.
• Ensure a better reputation for the product.

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Usability Testing

• A means for measuring how well people can use
  some human-made object, and how well test
  subjects respond in four areas
• Time How long it takes to complete tasks.
• Accuracy How many mistakes people made.
• Recall How much people remember.
• Emotional response How people feel.
• Re-test every 6 months.

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Web Page Design

• Simplicity
• Follow established web conventions
• Dont disable user preferences
• Use semantic tags whenever possible

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Dos and Donts of Achieving Usability

• Dos
• Black text White Background
• Text is a printable color
• Familiar location of navigation bars
• Encourage scrolling by splitting an image at the
  fold
• Limit annoyances
• Make buttons and links clear

• Donts
• Use boldface or all caps for long text
• Leave too much white space
• Alternate too frequently between centered and
  left aligned text
• Fix pages larger than 800 x 600 pixels

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References

• http//en.wikipedia.org/wiki/Usability
• http//en.wikipedia.org/wiki/Usability_testing
• http//dictionary.reference.com/browse/usability
• http//www.hq.nasa.gov/pao/portal/usability/index.
  htm
• www.usabilityfirst.com