Definition of usability

1. Mater of Arts in Communication Design
WEB DESIGN
Usability

2. Usability: formal definition
Usability
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3. Usability, definition
The extent to which a
product can be used by
specified users to achieve
specified goals with
effectiveness, efficiency,
and satisfaction in a
specified context of use.
(ISO 9241)
Usability
ISO 9241
Ergonomic requirements for office work
with visual display terminals (VDTs).
ISO 13407
Human-centred design processes for
interactive systems.
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4. Usability: declination
Usability
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5. Usability
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6. Learnability
• How easy is it for users to accomplish basic tasks the first time they
encounter the design?
• How easy is to remember?
Usability
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7. Efficiency
• Once users have learned the design, how quickly can they perform
tasks?
Usability
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8. Memorability
• When users return to the design after a period of not using it, how
easily can they re establish proficiency?
Usability
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9. Errors handling
• How many errors do users make, how severe are these errors, and
how easily can they recover from the errors?
Usability
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10. Satisfaction
• How pleasant is it to use the design?
Usability
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11. Not a surface matter
Usability
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12. Roberto Dadda
www.dadda.it
roberto@dadda.it
+39 338 775 22 03
Twitter, facebook, linkedin: robertodadda
Usability
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