Achieving and Balancing Consistency in User Interface Design

"...In human-computer user interfaces, stimuli include the following:
  • symbols—imagery—such as icons—that conveys information
  • codes—colors, sizes, weights, marks, and other graphic dimensions that may represent data values or invoke a metaphor
  • units of measurement—either for a particular numeric attribute or groups of related attributes
  • data formatsfor data in the form of text
  • terms—identifying the objects, classes, actions, and events in user interactions
  • abbreviations—for terms, including the names of the function and control keys that are assigned to commands
  • layouts—UI elements’ relative locations on a page or in a menu, window, or temporal sequence
Inconsistency occurs when the meanings of these stimuli vary—when stimuli / usage pairs are not the same. This implies there are two kinds of inconsistency...".

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