Usability and User Interface

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ITEC 334 Fall 2009Computer Programming in the
Web Era

• Usability and User Interface
• Professor J. Alberto Espinosa

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Usability

• Derives from the industrial engineering field of
  ergonomics how to design things so they are
  easy to use.It refers to the quality of a
  user's experience when interacting with a product
  or system and how well users can learn and use
  a product to achieve their goals and how
  satisfied they are with that process ... people
  who use the product can do so quickly and easily
  to accomplish their tasks usability.gov
• Other references http//www.usernomics.com/usabil
  ity.html

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Interface
The place at which independent and often
unrelated systems meet and act on or communicate
with each other Webster dictionary
Network
Hardware
User
System
Software
Software
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User Interface Design

• Also referred to as human computer interaction
  (HCI) is what the usability specialists do to
  build systems that are easy to use.
• HCI also derives from the field of ergonomics
  often referred to these days as human factors
  to include digital and virtual interaction, in
  addition to physical interaction.
• Other referencesCornell Univ
  http//ergo.human.cornell.edu/ahtutorials/interfac
  e.htmlVirginia Tech http//www.edtech.vt.edu/edt
  ech/id/interface/Carnegie Mellon
  http//www.usernomics.com/user-interface-design.ht
  ml

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A User Interface Can Be For

• Input into the system by the user for data entry
  or to query information from the system
• A display output (on screen or other output
  device) by the system to the user
• A printed output (on a printer or other output
  device)

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Diagramming the Interface with Storyboards

• User interfaces can be diagrammed as
  storyboards
• A storyboard is a series of drawings that depict
  how the system looks at the start of the
  operation and after each significant change to
  the look of the interface
• Is like a sequence of screenshots that follows
  the use case execution sequence

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Organization of a Storyboard
Storyboard Sequence
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A Bad Interface Storyboard
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General Quality Attributes for Usability in User
Interface Design

• Ease of use
• Intuitive use and navigation
• Consistency across screens
• Simplicity e.g., no clutter, no information
  overload, no busy graphics
• Exit/cancel options for users
• Forgiving
• Businesslike appearance
• Readable and good color contrast