3.9 KiB
| title |
|---|
| Heuristic Evaluation |
Heuristic evaluation
"Heuristics are strategies derived from previous experiences with similar problems" jacob nielsen and rolf molich
help find usability problems small set of 3-5 evaluators examine UI independently check for compliance with usability principles different evaluators will find different problems evaluators only communicate afterwaards findings are aggregated at the end
1 when?
- as part of need finding -> use experts to critique existing solutions
- before user testing -> identify minor issues before user testing
- before redesigning -> learn what works and what should change
- when you know there are problems but you need evidence -> "provide you with ammunition for design"
- before release -> smooth off rough edges
2 What
2.1 Process
2.1.1 Overview
Helps find problems in design
- 3-4 evaluators examine UI
- independent reviewers check for compliance with usability principles
- each evaluator will find different problems
- evaluators only communicate afterwards and the findings are aggregated can perform on working UI or sketches
2.1.2 Phases
- pre evaluation training ⇒ give evaluators needed domain knowledge and information on the scenario
- evaluation ⇒ individuals evaluate then aggregate result
- first as individuals
- then sit all together and aggregate
- Severity rating ⇒ determine how severe each problem is (priority). Can do first individually and then as a group
- Debriefing ⇒ review with design team
2.1.3 Individual
dont look search for heuristics individually just go through the app (like a user). If we find issues, we assign them to categories
step through design several times
- examine details, flow, an architecture
- consult list of usability principles
- … and anything else that comes to mind
which principles
- Nielsen's heuristics
- category specific heuristics
- e.g., design goals, competitive analysis, existing designs
use violations for redesign/fix problems
multiple evaluators because no one finds everything some will always find more than others (Rule of thumb 5 evaluators find ~75% of problems)
2.1.4 Severity rating
- independently estimate after viewing
- allocate resources to fix problems
- estimate need for more usability tests
- not problem
- cosmetic problem
- minor usability problem
- major
- catastrophe
2.1.5 Debreifing
- with evaluators observers and dev team
- discuss general characteristics of UI
- suggest potential imporvements
- dev team estimate effort to fix
- brainstorm solutions
2.2 Nielsen's ten heuristics
visibility of system status match between system and 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
2.3 Heuristic evaluation vs user testting
| heuristics | user testing |
|---|---|
| faster | slower |
| 1-2 hrs each | |
| results pre-interpreted | |
| ^ done by experts | |
| less accurate | more acurate |
| does not take into account actual users | can find issues that experts might not have |
| value to alternate methods | |
| ^ find dfferent issues |
2.4 Extra tips how to individual
- at least two passes each
- first get get feel for flow
- second to focus on specific elements
- if a system is "walk up and use" or evaluators are already domain expers ⇒ no assistance is needed
- otherwire might supply evaluators with scenarios
- each evaluators should list issues separately
- risk of repeating problematic aspect
- may not be possible to fix all problems
- where problems may be found
- single location in UI
- two or more locations that need to be compared
- problem with overall structure
- something is missing
- ambiguous with early prototypes
- sometimes ....