What is it?

• Developed by Jakob Nielsen
• Helps find usability problems in a UI 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 on sketches
• I like to use it for baselines

Phases of Heuristic Evaluation

1. Pre-evaluation training –give evaluators needed domain knowledge and information on the scenarios
2. Evaluation –individuals evaluate –aggregate results
3. Severity rating –determine how severe each problem is (priority) –Possible solution
4. Debriefing –discuss the outcome with design team

Heuristics

How to Perform

At least two passes for each evaluator

• first to get feel for flow and scope of system
• second to focus on specific elements

Assistance from implementers/domain experts

• If system is walk-up-and-use or evaluators are domain experts, then no assistance needed
• Otherwise might supply evaluators with scenarios and have implementers standing by

Where problems may be found

• single location in UI
• two or more locations that need to be compared
• problem with overall structure of UI
• something that is missing

Example Problem Descriptions

Example 1: Can’t copy info from one window to another

Violates “Recognition rather than recall” (H6)

The Fix: allow copying

Example 2: Typography uses mix of upper/lower case formats and fonts

Violates “Consistency and standards” (H4)

The Fix: pick a single format for entire interface

Severity Ratings

• Used to allocate resources to fix problems
• Estimates of need for more usability efforts
• Combination of –frequency –impact –persistence (one time or repeating)
• Should be calculated after all evaluations are done
• Should be done independently by all evaluators

0 – don’t agree that this is a usability problem

1 – cosmetic problem

2 – minor usability problem

3 – major usability problem; important to fix

4 – usability catastrophe; imperative to fix

Debriefing

• Conduct with evaluators, observers, and development team members
• Discuss general characteristics of UI
• Suggest potential improvements to address major usability problems
• Dev. team rates how hard things are to fix
• Make it a brainstorming session

Results of Using HE

• Single evaluator achieves poor results –only finds 35% of usability problems
• 5 evaluators find ~ 75% of usability problems
• why not more evaluators? 10? 20?
• adding evaluators costs more
• adding more evaluators doesn’t increase the number of unique problems found

Decreasing Returns

Note from Nielsen: These graphs are for a specific example

Learn more:

Nielsen Norman Group: UX Training, Consulting, & Research (nngroup.com)