Heuristic Evaluation and Expert Reviews

Heuristic Evaluation

  • Method for finding usability problems using usability principles (heuristics).
  • Issues discovered are rated by severity to prioritize fixes in iterations.
  • Each iteration should show a decrease in the number of issues.

Process:

  • Evaluators: Specialists in usability or user experience evaluate the interface.
  • Perspective: Evaluators act as experts, not as typical users.
  • Number of Evaluators: More evaluators increase the chance of detecting problems.
  • Timing: Can be done at any stage (wireframes, mock-ups, prototypes, implementation).
  • Outcome: Formal report identifying problems, their severity, and recommended solutions.

How to Conduct:

  1. Briefing Session:
    • Decide what to evaluate (prototype, product, system, wireframes).
    • Choose which heuristics to use (e.g., Nielsen's heuristics).
  2. Evaluation Period:
    • Experts work independently to avoid influencing each other.
    • First pass: Get a feel for the product.
    • Second pass: Focus on specific heuristics (e.g., Nielsen's 10 heuristics).
    • Assess conformance with usability principles.
    • Assess each heuristic on a scale (Nielsen's scale or a custom scale).
  3. Debriefing Session:
    • Experts come together to discuss findings.
    • Combine findings and propose solutions.
    • Make recommendations on how to fix issues.

Severity Scale (Nielsen's):

  • 0: No problem found.
  • 4: Critical problem that must be fixed immediately.

Priority Based on Severity:

  • Critical: Fix before the next iteration.
  • Major: High priority, fix by the next prototype.
  • Minor: Can be postponed, but expect it to be found in the next evaluation.

Benefits:

  • Identifies major and minor problems.
  • Applicable at any stage and on any type of interface.
  • Does not require actual users; can be done in-house.
  • Develops instincts on user experience, especially for newcomers.

Limitations:

  • Many types of heuristics exist; choosing the right one is crucial.
  • May identify only trivial problems; users will find different issues.
  • Evaluators may have bias due to their involvement in the project.
  • Does not replace user testing; needs to be paired with it.

Expert Reviews

  • Similar to heuristic evaluation, but broader in scope.
  • Experts focus on overall user experience, not just usability heuristics.
  • Consider guidelines, principles, and best practices.
  • Only uses specialists, possibly external, for unbiased reviews.
  • Can be conducted at any stage, but requires separate user testing.

Example:

  • Issue: Hamburger menu on a desktop website.
  • Problem: Hidden menu icons are easily overlooked by users on large screens.
  • Recommendation: Present all navigation options in the desktop layout.
  • Severity: High