Heuristic Evaluation

• Heuristic Evaluation is a discount usability technique
  • Developed by Jakob Neilsen
  • Find problems in a user interface design
  • Small set of evaluators evaluate based on usability principles (“heuristics”)
• One case study showed cost benefit ratio of 1:48!

Finding Problems

• Hard for a single evaluator to find all
• 19 evaluators find 16 problems in voice response system for bank
• Easy problems found by many evaluators
• Hard problems identified by those not finding many

Evaluators

Evaluators

• Nielsen recommends 3-5 because of diminishing returns

Evaluators

Performing

• Evaluator inspects interface alone
• Communication only when finished to aggregate
• In user study, typically want users to answer questions through exploration
• In HE, evaluator questions may be answered
  • May not be domain experts
  • Evaluator time valuable
  • Generally not given hints unless they ask or are clearly in need

Performing

• Typical HE lasts 1-2 hours
  • If longer needed, consider splitting into multiple sessions
• Evaluator goes through several times comparing interface to the heuristics

Reporting

• Reported with:
  • Written report by each evaluator
    • Formal record
    • Read/aggregated by an evaluation manager
  • Verbalization to an observer
    • Increase overhead reduced evaluator burden
    • Potentially faster results as no report by each

Output

• Output is list of usability problems
  • Reference those heuristics which were violated
  • Can not just say you do not like
  • Be specific and list each separately
    • Risk reintroducing the problem when another is solved
    • May not be possible to fix that specific one but related ones might be fixable

Debrief

• Sometimes might be worth debriefing
  • What went well is not covered
  • Discussion of possible design solutions

Heuristics

• Neilsen/Norman Group provides 10 well known usability heuristics

Visibility of System Status

• Users should understand current system status
• Facilitates learning outcomes of prior interactions to determine next steps
• Tips
  • Communicate clearly system state
  • Present feedback quickly, ideally immediately
  • Build trust through continuous communication

Match System & Real World

• Design should “speak” users language
  • Words, concepts, phrases
  • No internal jargon
• Use natural mapping when possible
• Tips
  • Users don’t need to look up definitions
  • Don’t assume your understanding = users
  • Perform user research to understand mental models, familiar terminology

Match System & Real World

User control and freedom

• Users make mistakes, provide clearly marked “emergency exit”
• Allows users to feel like they remain in control of system, reduces frustration
• Tips
  • Support Undo and Redo
  • Show a clear way to exit, e.g. Cancel button
  • Exit clearly labeled and discoverable

Consistency & Standards

• Users shouldn’t have to wonder whether different words, situations, actions mean same thing
• Follow platform and industry conventions
• People spend most of their time using systems other than yours
• Failing to do so increases cognitive burden
• Tips
  • Consider internal and external consistency
  • Follow established conventions

Error Prevention

• Good error messages important but preventing errors is better
• Eliminate error prone conditions or check for them
  • Slips - Unconscious errors
  • Mistakes - Conscious errors based on mismatch between mental model and design

Error Prevention

• Tips
  • Prioritize high-cost errors first, then frustrations
  • Avoid slips by providing helpful constraints and good defaults
  • Prevent mistakes by reducing or removing memory burdens, warning users, providing undo

Recognition Over Recall

• Minimize user memory load
  • Actions, elements, options visible
  • Avoid memory carryover from one part of interface to another
  • Information required to use design visible (e.g. labels)
• Tips
  • Offer help in context
  • Reduce information that needs to be remembered

Flexibility & Efficiency of Use

• Provide shortcuts
  • Hidden from novice users
  • Experienced and Inexperienced Users can interact
• Tips
  • Provide accelerators e.g. keyboard shortcuts
  • Provide personalization
  • Allow for customization

Aesthetic Minimalist Design

• Do not have irrelevant or rarely needed information on interfaces
• Extra information competes with relevant and reduces visibility
• Ensure visual elements of interface support users primary goals
• Tips
  • Focus on essential content and visual design
  • No unnecessarily distracting elements
  • Prioritize content and features that support primary goals

Help Users With Errors

• Help Users Recognize, Diagnose, Recover From Errors
• Error messages should
  • Be expressed in plain language (no error codes)
  • Precisely indicate problem
  • Constructively suggest solution
  • Presented so they will be noticed/recognized

Help Users With Errors

• Help Users Recognize, Diagnose, Recover From Errors
• Tips
  • Use traditional/redundant visuals like bold red text
    • Red alone not enough
  • Tell users what went wrong in their language, avoid jargon
  • Offer users a solution

Help and Documentation

• Best if system doesn’t need any explanation
• Still provide documentation to help users understand how to complete their tasks
• Should be
  • Focused on user’s task
  • Concise
  • List concrete steps
• Tips
  • Provide searching
  • Present in context when possible
  • List steps to be carried out

Questions

• Questions?