| name | experiment-design-readout |
| description | Turn a product or growth idea into a rigorous experiment brief and post-test readout format. |
| argument-hint | ["idea-or-problem"] |
Experiment Design Readout
Use this skill when the user wants to design, prioritize, or review product/growth experiments.
What this skill must produce
Always produce:
- Experiment brief
- Hypothesis
- Primary and secondary metrics
- Sample / ramp plan
- Implementation notes
- Decision rules
- Risks
- Post-test readout template
Working rules
- Prefer minimum viable tests.
- State the causal claim explicitly.
- Define what success and failure mean before the test launches.
- Use one primary metric.
- Guard against underpowered or low-quality tests.
- Distinguish operational guardrails from outcome metrics.
- Call out when a proposal is not suitable for an A/B test.
Step-by-step method
Step 1: define the problem
State the specific product or growth problem.
Step 2: define the hypothesis
Use this format:
If [change]
then [primary metric] will move by [expected direction / magnitude]
because [behavioral or product assumption].
Step 3: define the minimum viable test
Specify the smallest intervention that could validate or invalidate the hypothesis.
Step 4: define metrics
Choose:
- one primary metric
- 2-4 secondary metrics
- 2-4 guardrail metrics
Step 5: define the audience and segmentation
Specify:
- eligible population
- exclusions
- key segments to inspect
Step 6: define ramp and duration
Provide:
- initial ramp
- escalation path
- minimum duration
- sample size considerations
- stop conditions
Step 7: define interpretation rules
State what outcome would mean:
- launch
- iterate
- kill
- rerun with higher power / cleaner implementation
Step 8: define readout
Create the post-test structure before the test starts.
Output structure
Experiment brief
- Problem:
- User / segment:
- Proposed change:
- Why now:
Hypothesis
...
Test design
- Test type:
- Control:
- Treatment:
- Minimum viable version:
- Why this is the minimum viable test:
Metrics
Primary metric
- Name:
- Why it matters:
- Expected movement:
Secondary metrics
Guardrail metrics
Audience and segmentation
- Eligible audience:
- Exclusions:
- Segments to inspect:
Ramp / duration / sample plan
- Ramp plan:
- Target split:
- Duration:
- Sample / power caveats:
- Abort conditions:
Implementation notes
- Product / eng tasks:
- Analytics tasks:
- QA tasks:
- Dependencies:
Decision rules
- Launch if:
- Iterate if:
- Kill if:
- Rerun if:
Risks
- Underpowered test:
- Confounded implementation:
- Novelty effects:
- Long-term effects not captured:
- Maintenance cost vs gain:
Post-test readout template
Use this exact structure after the test finishes:
- Experiment summary
- What happened on the primary metric
- What happened on secondary and guardrail metrics
- Segment-level observations
- Did the result support the hypothesis?
- Most likely explanation
- Decision
- Follow-up actions
- New questions created
Special instructions
If the requested test is pricing-related, state plainly when classic A/B testing is a bad fit due to low sample size, customer fairness concerns, or poor statistical power. Offer an alternative such as:
- pricing research
- segmented rollout
- minimum viable pricing test
- sales-assisted validation
- willingness-to-pay study
If the requested test has major irreversible downside, recommend a smaller-risk pretest or staged rollout.