# Test hypothesis writer

> Use before building a test, when you have an idea but no properly stated hypothesis.

## Fill in before running

- `{{IDEA}}`
- `{{EVIDENCE}}`
- `{{LOCATION}}`
- `{{PRIMARY_METRIC}}`
- `{{BASELINE_RATE}}`
- `{{WEEKLY_VOLUME}}`

## Prompt

```
You are helping write a testable hypothesis. Do not accept a vague idea - force it into a falsifiable statement.

THE IDEA: {{IDEA}}
EVIDENCE THAT PROMPTED IT: {{EVIDENCE}}
PAGE OR FLOW: {{LOCATION}}
PRIMARY METRIC: {{PRIMARY_METRIC}}
CURRENT BASELINE RATE: {{BASELINE_RATE}}
WEEKLY TRAFFIC OR SESSIONS ON THAT PAGE: {{WEEKLY_VOLUME}}

Produce exactly these fields:
1. Problem statement - what we believe is going wrong, in behavioural terms, not design terms.
2. Evidence grade - Strong (quantitative and qualitative), Moderate (one source), or Weak (opinion). Say which.
3. Hypothesis - in the form: Because [evidence], we believe that [change] for [audience] will cause [effect on primary metric]. We will know this is true when [measurable outcome].
4. Primary metric and one guardrail metric that would tell us the change caused harm elsewhere.
5. Minimum detectable effect that is realistic at this traffic level, and roughly how long the test would need to run. Show the reasoning. If the traffic is too low to detect anything sensible, say so plainly and suggest a non-test alternative such as a painted door or a qualitative study.
6. What result would make us reject the hypothesis.
7. What we learn if it is null - state this before running, not after.

Rules: if the evidence is Weak, say the test should not be prioritised and explain why. Do not estimate uplift percentages you cannot support. No em dashes.
```

## Getting a better result

- Give the real baseline rate, otherwise the sample size reasoning is theatre.
- If it grades the evidence as Weak, go and get the evidence rather than running the test.
- Write point 7 down and keep it - it is what stops a null result being written off as a failure.

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From the QuQi prompt library - https://www.quqi.io/prompts/test-hypothesis-writer