A vision model walking your screens against Nielsen's heuristics and platform HIGs catches the findable problems in minutes — visibility gaps, inconsistent patterns, missing feedback. This playbook runs that pass as preparation for real usability data, with you validating every severity and discarding the false positives it will absolutely produce.
Workflow area: Ideation & Critique · Tier: Core · Hands-on time: ~30 minutes
Heuristic evaluation was always the cheap, fast, imperfect method: expert judgment against known principles, catching perhaps a third to a half of real problems while flagging some that users never hit. A vision model running the same heuristics inherits all of that — including the false-positive rate — at a fraction of the cost. That makes the economics excellent and the epistemics dangerous. Used before research, it clears the underbrush so studies find the deep problems. Used instead of research, it launders "an AI guessed" into "an evaluation found." This playbook keeps it firmly on the right side of that line.
Capture the flow in order, at real fidelity. Export screens in sequence — entry, core task, confirmation — at readable resolution. Include the states you have (empty, error) because state gaps are half of what heuristic review catches. Number the files; the model will cite them.
Run the review with heuristics named and scope pinned. In Claude or ChatGPT with images attached:
You are performing a heuristic evaluation of this flow.
Context: [PRODUCT, USER, THE TASK THIS FLOW SERVES]
Screens attached in task order, numbered.
Evaluate against:
- Nielsen's 10 usability heuristics (name the specific heuristic
per finding)
- [iOS HIG / Material Design / your platform] conventions for
navigation, controls and feedback
For each finding:
- screen number and the specific element (location on screen)
- heuristic or guideline violated, by name
- what the user problem would be, as a concrete scenario
- severity 1-4 (Nielsen scale: cosmetic → catastrophic) with
one line of reasoning
Rules: findings must reference visible evidence in the screens.
Do not assume behavior you cannot see — flag "cannot assess
[hover states / motion / loading] from static images" explicitly.
No praise, no summary of what works.
Interrogate the suspicious findings. For any finding that smells off, push back: "Screen 3, finding 7 — the model says the filter state is invisible. Describe exactly what pixels indicate filter state." The model either points at real evidence or retracts. This one habit removes most false positives before they cost anyone time.
Validate severity yourself — every single rating. The model rates severity by rule; you rate it by knowing your users, their frequency on this flow, and the cost of the error. Re-grade the list:
# SCREEN FINDING AI SEV MY SEV NOTE
3 2 No feedback after "Save" 3 4 Core action, hit
dozens of times/day
7 3 Filter state not visible 3 1 Power-user screen;
state shown in URL
9 4 Destructive delete lacks 4 4 Confirmed; ship
confirmation blocker
Findings the model could not assess from statics (motion, latency, focus order) go to a separate list for pb-31's artifact-side pass or real testing — not silently dropped.
Ship the pre-screen as prep, labeled as such. The output is a fix list for the violations you confirmed, plus a research agenda: the ambiguous findings become tasks and questions for your next usability study. Title the document "AI-assisted heuristic pre-screen" — the label is the honesty mechanism that keeps it from being quoted as user research in three months.
Screens of unreleased features are confidential — run reviews in your organization's approved AI workspace, and check that screenshots do not contain real customer data before uploading; production screens with live user content need scrubbing first.
An AI heuristic review is a cheap expert pass with an unknown error rate — name the heuristics, demand pixel evidence, re-grade every severity yourself, and let it sharpen the research it must never be allowed to replace.