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A Practical Guide to the CIF: Usability Measurements

Mary Theofanos, Brian Stanton, Nigel Bevan. A Practical Guide to the CIF: Usability Measurements. Markus Lappalainen 27 November 2008. Real-Life Story: GSA 1/2. 2004 U.S. General Services Administration Denver and Philadelphia offices.

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A Practical Guide to the CIF: Usability Measurements

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  1. Mary Theofanos, Brian Stanton, Nigel Bevan A Practical Guide to the CIF:UsabilityMeasurements Markus Lappalainen 27 November 2008

  2. Real-Life Story: GSA 1/2 2004 U.S. General Services Administration Denver and Philadelphia offices “People can’t figure out how to do their jobs on the new system.” “…someone bursts into tears almost hourly.” “Saving a file took few clicks, now it takes 15.” A Practical Guide to the CIF: Usability Measurements

  3. Real-Life Story: GSA 2/2 • Development of this system lacked sufficient consideration for usability • Article: • How to measure usability? • How to incorporate usability measures into development process? A Practical Guide to the CIF: Usability Measurements

  4. CIF Is the Tool • Common Industry Format for Usability Test Reports • Standard method for reporting usability test findings from quantitative measurements • Basically a template for usability test reports ISO/IEC 25062 2006 Software Engineering - Software product Quality Requirements and Evaluation (SQuaRE) – Common Industry Format (CIF) for Usability Test Reports Theofanos et al. A Practical Guide to the CIF: Usability Measurements

  5. CIF Process A Practical Guide to the CIF: Usability Measurements

  6. Usability Measuring 1/3 CIF measures • Effectiveness:accuracy & completeness of tasks • Efficiency:used resources vs. accuracy & completeness • Satisfaction:how well product meets expectations ISO 9241-11 “Usability is 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.” A Practical Guide to the CIF: Usability Measurements

  7. Usability Measuring 2/3 • First we must define • Primary users and their characteristics • Primary or representative tasks • Context of use In the GSA case Users: Various clerks and officials Tasks: Process orders and payments under pressure Context: Office cubicles, government desktops A Practical Guide to the CIF: Usability Measurements

  8. Usability Measuring 3/3 • Identify what to measure; CIF suggests • Effectiveness: Completion percentage, error frequency, amount of help needed • Efficiency: Time on task • Satisfaction: Measure with questionnaires A Practical Guide to the CIF: Usability Measurements

  9. CIF Process A Practical Guide to the CIF: Usability Measurements

  10. UsabilityRequirements 1/2 • Using baseline, create Usability Requirements • URs must be sufficiently detailed to support product development • URs are also used as validation criteria for development results CIF format reports facilitate objective comparison of current and new system A Practical Guide to the CIF: Usability Measurements

  11. UsabilityRequirements 2/2 • Format for UR’s: CISU-R* which includes • Context of use (intended users & environment) • Usability measures (effectiveness, efficiency & satisfaction metrics and target values) • Test method (validation protocols) Demand: New System ≥ Current System *Common Industry Specification for Usability-Requirements, IUSR 2006. A Practical Guide to the CIF: Usability Measurements

  12. CIF Pocess A Practical Guide to the CIF: Usability Measurements

  13. Measuring New System Usability • Redo all Usability Measurements done in first stage, but now with new system • Compare formal documents • CIF report for current system • UR’s for the new system • CIF report for new system  Is the new system (as) usable (as wanted)? A Practical Guide to the CIF: Usability Measurements

  14. ArticleSummary • How to apply CIF in product development process (the three-arrow chart) • CIF offers objective way to identify what a product needs to be successful (from usability point of view) • CIF documents and process standardize usability development  easier to communicate usability facts to stakeholders A Practical Guide to the CIF: Usability Measurements

  15. Synthesis • We have seen several models for usability on this course • In CIF usability is also defined by the familiar ISO 9241 • However the CIF process is more practical and clearly aimed for business use A Practical Guide to the CIF: Usability Measurements

  16. Evaluation 1/2 • Black box approach leaves implementation open but requirements need to be expressed clearly (formal approach like CIF will help) • What if development fails at stage 3? • Usability test results seem to vary by tester, subjects, tasks etc. [1] • Make the tests as representative as possible! A Practical Guide to the CIF: Usability Measurements

  17. Evaluation 2/2 • CIF can serve as reference when building development process • Real world has also many other measures! • Usability development is expensive [1], CIF could help to justify costs • CIF based development ties stakeholders together, communication is likely to reduce problems A Practical Guide to the CIF: Usability Measurements

  18. Reference [1] Lindgaard, G. et al, Usability Testing: What Have We Overlooked?, 2007 A Practical Guide to the CIF: Usability Measurements

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