Imported from jabrena/plinth (skills/023-assumption-analysis/SKILL.md). Install upstream with npx skills add jabrena/plinth --skill 023-assumption-analysis. Copyright stays with the author (Apache-2.0).

Assumption Analysis

Guide production of explicit Assumptions, a list of Unknowns, and a Validation plan for a problem under exploration. This is an interactive SKILL.

What is covered in this Skill?

• Surfacing assumptions implicit in the problem frame and root-cause findings
• Distinguishing an assumption (believed true, not yet verified) from an unknown (not yet known either way)
• Ranking assumptions and unknowns by impact and confidence
• Defining a validation plan that names how and when each risky assumption or unknown will be checked
• Feeding assumption and unknown findings into 024-context-mapping and the remaining Functional Specification lenses

Constraints

Make assumptions and unknowns explicit before they become undiscussed risk. When this technique is orchestrated by another workflow, the orchestrator owns clarifying-question sequencing; when applied standalone, ask directly.

• MUST read references/023-assumption-analysis.md before applying Assumption Analysis guidance
• MUST state each assumption as a falsifiable claim believed true but not yet verified
• MUST distinguish assumptions (believed true) from unknowns (not yet known either way)
• MUST rank assumptions and unknowns by impact if wrong and by current confidence
• MUST define a validation plan naming how and when each high-impact, low-confidence assumption or unknown will be checked
• MUST NOT invent an assumption, unknown, or validation step when the available content is vague or ambiguous; flag the gap for a clarifying question instead

When to use this skill

• Surface the assumptions behind this problem
• List the unknowns for this issue
• Build a validation plan for these assumptions
• Apply assumption analysis before design begins
• Draft the Assumption Analysis section of a Functional Specification

Workflow

1. Read the Reference

Read references/023-assumption-analysis.md, then review the problem frame and root-cause findings for implicit beliefs.

2. Surface Explicit Assumptions

State each assumption as a falsifiable claim believed true but not yet verified.

3. List Unknowns

List facts that are not yet known either way, distinct from assumptions.

4. Rank by Impact and Confidence

Rank assumptions and unknowns by impact if wrong and by current confidence, prioritizing high-impact, low-confidence items.

5. Define the Validation Plan

Name how and when each high-priority assumption or unknown will be validated.

6. Report the Assumption Analysis

Report the Assumptions, Unknowns, and Validation plan, and flag any item left open pending a clarifying answer.

Reference

For detailed guidance, examples, and constraints, see references/023-assumption-analysis.md.