COAP:COAP-3150 - week 6
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Interaction styles
- HCI interaction styles - based on Shneiderman
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, 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
- Usability
- Interaction design
- Design and usability methods and techniques
- User interaction and user interface design - definitions and distinction
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.
- Why You Only Need to Test with 5 Users - 5 users represent 80% of problems
Examples
- Bad usability in (web) design
Designing interaction
Webforms (self-study)
Javascript (self-study)
See and Javascript tutorial - basics
Publish a site
- Assignment 8 - Functional prototype
Links
References
- ↑ Oli Gardner, The 5 second rule, http://unbounce.com/landing-page-optimization/the-5-second-rule-best-sites-of-2009-part-1/
- 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.