COAP:COAP-3150 - week 6: Difference between revisions

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==Interaction styles==
==Interaction styles==
*[http://www.interaction-design.org/encyclopedia/interaction_styles.html HCI interaction styles] - based on Shneiderman
See detailed descriptions, examples (screen shots) and advantages and disadvantages at [http://www.interaction-design.org/encyclopedia/interaction_styles.html HCI interaction styles] - based on Shneiderman
*'''Command language (or command entry)''' - e.g. unix commands, for repeated and expert use
*'''Form fill-in''' - e.g. search forms, for high guidance of formalized information
*'''Menu selection''' - e.g. navigation, for restricted choices
*'''Direct manipulation'''  - e.g. software palettes, icon buttons, drag and drop, for reducing memory load of complex tasks, heavily based on graphic representations


==Usability testing==
==Usability testing==

Revision as of 10:21, 24 February 2012

Interaction styles

See detailed descriptions, examples (screen shots) and advantages and disadvantages at HCI interaction styles - based on Shneiderman

  • Command language (or command entry) - e.g. unix commands, for repeated and expert use
  • Form fill-in - e.g. search forms, for high guidance of formalized information
  • Menu selection - e.g. navigation, for restricted choices
  • Direct manipulation - e.g. software palettes, icon buttons, drag and drop, for reducing memory load of complex tasks, heavily based on graphic representations

Usability testing

Heuristics and quick tests

The 5 second rule[1]

Upon landing on a homepage a user should be able to figure out in 5 seconds - The 5 second rule

  • What is it about?
  • Do I care?
  • Is it trustworthy?
  • How do I participate?
  • Is it newsworthy?

Ten Usability Heuristics by Jakob Nielsen

Reduced to five in Usability 101.

  • Learnability: How easy is it for users to accomplish basic tasks the first time they encounter the design?
  • Efficiency: Once users have learned the design, how quickly can they perform tasks?
  • Memorability: When users return to the design after a period of not using it, how easily can they reestablish proficiency?
  • Errors: How many errors do users make, how severe are these errors, and how easily can they recover from the errors?
  • Satisfaction: How pleasant is it to use the design?

Borrowing from Davis' Technology acceptance model, Nielsen defines useful web design as

  • Utility = whether it provides the features you need.
  • Usability = how easy & pleasant these features are to use.
  • Useful = usability + utility.

Ergonomic criteria for evaluating interfaces and interactions

Bastien and Scapin (1997), through studies conducted, showed usability to be based on criteria that place significantly les importance on a systems information efficiency than Nielsen. Their criteria for ergonomics of interfaces focus strictly on the system's usability (manageability):

  • Guidance: incite, orient user, group information (proximity, repetition), immediate feedback, legibility
  • User workload: diminish cognitive effort for user, be brief, minimal actions, reduce information density
  • User explicit control: allow users explicit control of their actions
  • Adaptability: flexible, environment adjusts to accommodate user preferences
  • Error management: help avoid or allow for the correction of errors, meaningful error messages
  • Consistency: keep interface consistent for particular context, change for change of context.
  • Significance of codes: coherence between signs and the object or action to which they refer
  • Compatibility: content and actions are compatible with the habits and practices of target public

Related pages

Generating authentic user tasks

See Scenario-based usability engineering

Designing the test

Three basic steps to usability testing from Nielsen's Usability 101:

  • Get hold of some representative users, such as customers for an e-commerce site or employees for an intranet (in the latter case, they should work outside your department).
  • Ask the users to perform representative tasks with the design.
  • Observe what the users do, where they succeed, and where they have difficulties with the user interface.
  • Shut up and let the users do the talking.

Examples

Bad usability in (web) design

Designing interaction

Webforms (self-study)

See HTML forms tutorial

Javascript (self-study)

See and Javascript tutorial - basics

Publish a site

Assignment 8 - Functional prototype

Described in week 6 Learning module

Links

References

  • NIELSEN, J., (1993) Usability engineering. Boston, Academic Press.
  • SCAPIN, D.L. and BASTIEN, J.M.C. (1997). Ergonomic criteria for evaluating the ergonomic quality of interactive systems. Behavior & Information Technology, 1997, 17 (4/5), 220-231.
  • SHNEIDERMAN, B. (1992). Designing the user interface : strategies for effective human-Computer-Interaction. (Chap 3, 4 and 5). 2nd ed., Addison-Whesley Publishing Company.