Download
1 / 18
180 likes | 187 Vues
Heuristic Evaluation and Discount Usability Engineering. Taken from the writings of Jakob Nielsen – inventor of both. Heuristic Evaluation. Context – part of iterative design Goal – find usability problems Who – small set of evaluators
E N D
Heuristic Evaluation and Discount Usability Engineering Taken from the writings of Jakob Nielsen – inventor of both
Heuristic Evaluation • Context – part of iterative design • Goal – find usability problems • Who – small set of evaluators • How – study interface in detail, compare to small set of principles
Ten Usability Heuristics • Visibility of system status • Match between system and the real world • User control and freedom • Consistency and standards • Error prevention • Recognition rather than recall • Flexibility and efficiency of use • Aesthetic and minimalist design • Help users recognize, diagnose, and recover from errors • Help and documentation
How to Conduct a Heuristic Evaluation • More than one evaluator to be effective. • Each evaluator inspects the interface by themselves • General heuristics may be supplemented • Results can be oral or written • Evaluator spends 1-2 hours with interface • Evaluator goes through interface > 1 time • Evaluators may follow typical usage scenarios • Interface can be paper
Heuristic Evaluation Results • List of usability problems • With principle violated • With severity • NOT fixes • May have debriefing later to aid fixing • Discount usability
Usability Problem Location • Single Location • Two/Several Locations • Overall Structure • Something Missing
Severity • Help focus repair efforts • Help judge system readiness • Factors in Severity: • Frequency • Impact • Persistence • Market impact • Scale severity to a number • May wait on severity
H.E. Complementary w/ Usability Testing • Each will find problems that the other will miss • H.E. Weakness – finding domain specific problems • Don’t H.E. and Usability Test same prototype version
Discount Usability Engineering • “It is not necessary to change the fundamental way that projects are planned or managed in order to derive substantial benefits from usability inspection” • 6% of project budget on usability • 18% of respondents used usability evaluation methods the way they were taught
More Discount Usability Engineering • Cost projection to focus on usability may be reduced • “Insisting on only the best methods may result in having no methods used at all” • 35% of respondents used 3-6 users for usability testing • Nielsen and others suggest 50-1 ROI
Elements of Discount Usability Engineering • Scenarios • Simplified Thinking Aloud • Heuristic Evaluation
Scenarios • Take prototyping to extreme – reduce functionality AND number of features • Small, can afford to change frequently • Get quick and frequent feedback from users • Compatible with interface design methods
Simplified Thinking Aloud • Bring in some users, give them tasks, have them think out loud • Fewer users in user testing
Heuristic Evaluation • Fewer principles etc to apply • Compare interface to previous version or competitor • Ensure tasks are parallel • “Within Subjects” recommended • Counter balance order
Stages of Views of Usability in Organizations • Usability does not matter. • Usability is important, but good interfaces can surely be designed by the regular development staff as part of their general system design. • The desire to have the interface blessed by the magic wand of a usability engineer. • GUI/WWW panic strikes, causing a sudden desire to learn about user interface issues. • Discount usability engineering sporadically used. • Discount usability engineering systematically used. • Usability group and/or usability lab founded. • Usability permeates lifecycle.
