Experiment Writeup

Help PMs document experiment results in a structured format. Turns raw data into clear narratives with hypothesis, methodology, results, learnings, and decision.

When to Use

• Documenting A/B test outcomes
• Writing up feature experiment results
• Sharing experiment learnings with stakeholders
• Creating a record for future reference
• When asked "help me write up the results"

Process / Template

1. Gather the Data

• Hypothesis (original statement)
• Experiment design (variants, duration, sample size)
• Primary, secondary, and guardrail metric results
• Statistical significance (p-values, confidence intervals)
• Any qualitative feedback or observations

2. Structure the Writeup

Hypothesis

• Restate the original hypothesis
• Brief context on why we ran this

Methodology

• Variants tested (control vs. treatment)
• Duration and sample size
• Target segment
• Any caveats (traffic issues, external events)

Results

• Primary metric — direction, magnitude, significance
• Secondary metrics — supporting or conflicting signals
• Guardrail metrics — did anything regress?

Learnings

• What did we learn? (beyond the numbers)
• Surprises or unexpected findings
• Implications for future work

Decision

• Ship / Iterate / Kill
• Rationale for the decision
• Next steps (if iterating)

3. Write Clearly

• Lead with the decision and key takeaway
• Use plain language; avoid jargon
• Include numbers with context (e.g., "+12% vs. control")
• Call out statistical significance explicitly

Output

A structured Experiment Writeup suitable for:

• Stakeholder sharing (Slack, email)
• Internal documentation
• Experimentation platform notes
• Retrospectives and planning

Format: concise, scannable, decision-oriented. Typically 1–2 pages or equivalent in markdown.