The model locates which link contains the problem
Aliases: gulf of execution · gulf of evaluation · stage diagnosis
What it is
The value of the seven stages is to split “users cannot use it” into repairable questions. Failure to find an action is a Gulf of Execution; failure to see what the system did or whether the goal was met is a Gulf of Evaluation. Locating the stage selects among visibility, mapping, feedback, and recovery designs.
Why it happens
One symptom has many roots. A user may not tap Export because the entry is invisible (plan/specify), the term is unfamiliar (specify), the button is disabled without reason (perform), or completion is unclear (perceive/interpret). Asking stage by stage whether users can form a goal, see options, specify action, perform, perceive, interpret, and compare maps symptoms to mechanisms and acceptance checks.
Studying it
Combine recordings, think-aloud, and logs to annotate each failed segment: goal statements, available actions, performance attempts, feedback, and timing. Measure transition error rate, time, backtracking, and help seeking per stage. Test counterfactual repairs for the same problem—add an entry, change a label, enable a control, or display a result—to see which link removes the failure.
Where it stops holding
Do not force every issue into the seven stages; social workflow, business rules, and system faults may act together. Stage location starts diagnosis but does not replace severity, frequency, and business-impact analysis. Automated transitions of skilled users may not appear explicitly in tests.
Applying it
- Review core tasks with a seven-column diagnostic: goal, plan, specify, perform, perceive, interpret, compare.
- For each bottleneck, record what users say, interface state, evidence, and repair direction.
- Map execution gulfs to discoverability, mapping, and constraints; map evaluation gulfs to feedback, status, and timing.
- Replay the same task after repair to confirm the bottleneck moves to success rather than disappearing into description.
Related
- Same group: B4.01.1 Goal, plan, specify, perform, perceive, interpret, and compare are seven stages · B4.01.2 Stages can skip and loop rather than form a strict linear sequence
- Nearby: B3.01 Visibility of System Status · B3.09 Error Recognition, Diagnosis, and Recovery
- Search terms:
gulf of execution·gulf of evaluation·stage-based diagnosis