Gap Analysis
Core principle: Every gap between what users believe is happening and what's actually happening is a design failure waiting to surface. Map the gaps, find the structural causes.
Mental Model Gaps
For each touchpoint or step, document:
| Column | What it captures |
|---|---|
| User belief | What users predict will happen, based on cues and prior experience |
| System reality | What actually happens — read routes, controllers, views, mailers |
| Consequence | Confusion, error, churn, support load — the cost of the gap |
| What would close it | The design change that aligns model to reality |
Code analysis reveals system reality directly. User beliefs require inference from labels, copy, affordances, and known interaction patterns. Separate confirmed from inferred.
Moments of Truth
Every crossing of the line of interaction is a moment of truth — an encounter with outsized power to shape trust. For each crossing, capture: expected mental model, likely emotional state, failure modes, and visible evidence shaping perception. Cross-reference the blueprint's interaction line to find these crossings.
Information Scent
Assess whether labels, cues, and surrounding context help users estimate the value of each path. Weak scent causes confusion and backtracking even when the right answer exists in the system. Misleading scent is worse — it builds false confidence. Rate each location: strong, weak, or misleading.
Progressive Disclosure Check
Evaluate complexity timing across three phases. Early (onboarding, first contact): overwhelmed or appropriate? Mid (core task): sufficient or noisy? Late (completion, edge cases): starved or adequate? Flag phase mismatches — too much too early, too little too late.
Sequencing
This skill is most powerful after service-design:service-blueprint and service-design:empathy-analysis exist for the slice. It cross-references both: the blueprint provides the interaction line and backstage structure, the empathy analysis provides the emotional and informational layer. Can run standalone but yields less precise results.
Confidence Discipline
Tag every claim: [confirmed] (verified in code, docs, or data), [hypothesis] (inferred from patterns or analogous systems), or [gap] (unknown). Mental model gaps derived from code analysis are [confirmed] on the system-reality side; the user-belief side is almost always [hypothesis] without direct research. Note what would confirm each hypothesis.
Output
Write to docs/service-design/<slice>/gap-analysis.md using the template at service-design/templates/gap-analysis.md. Populate Mental Model Gaps, Moments of Truth, Information Scent, Progressive Disclosure Check, and Priority Gaps sections.