How Many Software EngineersDoes It takes to Change a Light bulb?
How Many Usability EngineersDoes it takes to change a Light bulb?
• Usability Engineering is an Important aspect of any product Development.• People rarely use the recommended usability engineering methods.• One important reason usability engineering is not used in practice is the cost of using the techniques or rather perceived cost.
“le mieux est lennemi du bien" (The best is the enemy of the good) [Voltaire 1764]Heuristic Evaluation is a Discount Usability Technique, It is not costly like usingRegular Usability Principles, but helps in finding several usability problems in yourProduct.
Heuristic Evaluation Technique• Developed by Jacob Nielsen.• It’s a Discount Usability Technique.• It’s a Critique based approach.• Helps ﬁnd usability problems in a design.• Small set (3-5) of evaluators examine UI.• Independently check for compliance with usability principles (“heuristics”).• Different evaluators will ﬁnd different problems evaluators only communicate afterwards.• Findings are then aggregated.• Can perform on working UI or sketches.
Phases of Heuristic Evaluation1. Pre-evaluation training: give evaluators needed domain knowledge and information on the scenario.2. Evaluation: individuals evaluate (against defined Heuristics) and then aggregate results.3. Severity rating: determine how severe each problem is (priority). Can do ﬁrst individually and then as a group.4. Debrieﬁng: review with design team.
Severity Ratings0 - don’t agree that this is a usability problem1 - cosmetic problem2 - minor usability problem3 - major usability problem; important to ﬁx4 - usability catastrophe; imperative to ﬁx
Ten Design Heuristics• Show system status• Familiar metaphors & language• Control & freedom• Consistency• Error prevention• Recognition over recall• Flexibility & efficiency• Aesthetic & minimalist design• Recognize, diagnose, & recover from errors• Help
1. Show System StatusShow Time• Feedback depends on response time<1s: just show outcome~1s: feedback that activity is underway Hour Glass>>1s: Show fractional progress; time
Show: Next steps• Amazon purchase reply
2.Familiar Metaphors & LanguageFamiliar Metaphors• Real world Metaphors Like Trash, files, Folders upload My Documents
3. User Control and Freedom• Freedom to Undo and Redo
Freedom to Explore
4. Consistency and Standards• Consistent Layout
5.Error Prevention• Prevent Data Loss
Prevent Bad Input
Prevent Unnecessary Constraints
6.Recognition over Recall• Recognition with Previews
7.Flexibility and Efficiency• Flexible Default with options
8.Aesthetic & Minimalist Design• Above the Fold
9. Recognize, Diagnose, & Recover from Errors• Make Problem Clear.