# 4 · Check: the right thing, for the right person The UI review (UI design, `5-review.md`) asks whether what you built is well made. This part asks whether it's the right thing. Do it before you say done on any job sized **full** in `START.md`, and keep the reasoning where the next session will find it. --- ### K1 · Walk it through as the person **Rule:** Before saying done, use what you built as the person from W1 would, in their situation (W2), with realistic content. Start from nothing, do the whole job, and stop where they'd stop. Note every point where they'd be confused, wait, or need you to explain something. Fix those first. **Why:** You know how it's meant to work. They don't, and they won't read instructions. Walking it through as them is the closest you can get to watching them use it. **Agent trap:** testing features one at a time ("create works, edit works, delete works") instead of doing the job. Every part passes, and the job still takes eleven steps and a guess. **Check:** did you do the full job end to end, as the person? How many steps did it take, and could any of them go? > **In ihumane Pro** (https://ihumane.ai/#pricing): > - K2 · Hold it against the problem, the success line, and today > - K3 · Write the product brief where the next session finds it > - K4 · Report the product decisions, not only the build ## Template: PRODUCT.md Copy this into `PRODUCT.md` and fill it in. Mark each line **known** (they said it, or you found it) or **assumed**. ```markdown # PRODUCT.md > Read this before adding or removing features. Update it when who it's for, > the problem or the scope changes. > Last updated: by ## For - Person: (known | assumed) - Not for: - Who decides / pays, if different: ## Job When , I want to , so I can . ## Today - They use: - It does well: - Switching costs: ## Problem ## Different because ## Success - Looks like: - We'd notice by: ## This version - Core loop: - Next (ranked): ## Left out on purpose | Feature | Why not now | Would add when | |---------|-------------|----------------| | | | | ## Open questions - ``` --- ## Check - [ ] You did the whole job as the person, from an empty start, with realistic content. - [ ] You answered the three K2 questions, and reported any "no" or "unsure". - [ ] `PRODUCT.md` (or the project's existing notes) holds the current brief, with known and assumed marked. - [ ] `DESIGN.md`, if it exists, agrees with the brief. - [ ] Your report names who it's for, what's left out and why, and what you assumed. - [ ] At most one question at the end.