Assumption Mapper Skill
Surface and prioritize the untested assumptions embedded in any product plan before development begins.
Required Inputs
Ask the user for these if not provided:
- Product brief, PRD, or concept description (even rough notes work)
- Stage (concept / discovery / pre-build / post-launch — affects which assumptions matter most)
Process
- Read the provided brief, PRD, or concept description
- Extract assumptions across four categories:
- Desirability (do users want this?)
- Feasibility (can we build it?)
- Viability (will it sustain the business?)
- Usability (can users actually use it?)
- Score each assumption:
- Confidence (1-5): How sure are we this is true?
- Impact (1-5): How badly does the plan fail if this assumption is wrong?
- Priority = Impact − Confidence (higher = test first)
- Validate completeness — Ensure at least one assumption per category. If a category is empty, re-read the brief looking specifically for that type.
- Output a ranked list with recommended validation methods
Output Structure
Assumption Map: [Feature/Product Name]
| Assumption | Category | Confidence | Impact | Priority | Validation Method |
|---|---|---|---|---|---|
| [assumption] | [type] | [1-5] | [1-5] | [score] | [method] |
Critical Assumptions (Impact 4+ and Confidence 2 or below)
[Flagged items with detailed validation recommendations]
Top 3 Assumptions to Validate First
[Detailed recommendations including specific research method, estimated effort, and what the result would change]
Example (Partial)
Input: "We're building a self-serve onboarding flow to reduce time-to-value for SMB customers."
| Assumption | Category | Confidence | Impact | Priority | Validation Method |
|---|---|---|---|---|---|
| SMB users can complete onboarding without human help | Usability | 2 | 5 | 3 | Unmoderated usability test (n=8) |
| Faster onboarding correlates with higher retention | Viability | 3 | 4 | 1 | Cohort analysis of current onboarding times vs. 90-day retention |
| The current onboarding is the primary reason for slow time-to-value | Desirability | 2 | 4 | 2 | User interviews with recent churned SMB accounts |
Anti-Patterns
- Do not only surface desirability assumptions — feasibility and viability assumptions are equally likely to kill a product and are often overlooked
- Do not assign high confidence to an assumption just because it hasn't been challenged yet — absence of evidence is not evidence
- Do not recommend "user interviews" as the validation method for every assumption — some assumptions require quantitative data, competitive analysis, or technical spikes
- Do not list assumptions that cannot be tested — every assumption in the map must have a plausible validation method, or it should be flagged as unknowable and treated as a risk
Quality Checks
- At least one assumption per category (Desirability, Feasibility, Viability, Usability)
- All Impact 4+ / Confidence 2− assumptions flagged as CRITICAL
- Each validation method is specific (not just "do research" — name the method and sample size)
- Priority scores are consistent (Impact − Confidence, higher = more urgent)