mohitagw15856
036511ab3e
Broadens both reach (more tools) and content types (an MCP server), continuing the multi-platform story. Windsurf + Aider: - build-exports.mjs gains two platforms: exports/windsurf/*.md (workspace rules, trigger: model_decision) and exports/aider/*.md (conventions for `aider --read`). Now 5 platforms (ChatGPT, Gemini, Cursor, Windsurf, Aider). - install.sh + bin/cli.mjs install both (windsurf -> .windsurf/rules, aider -> .aider/skills with a --read hint); generated README index is excluded from copies. - One-line windsurf-install.sh / aider-install.sh wrappers for parity. MCP server (new content type): - mcp/server.mjs — zero-dependency stdio MCP server exposing list_skills, search_skills, get_skill. Published as a second bin (pm-claude-skills-mcp). Logs to stderr; reads bundled skills/ at startup. mcp/README.md documents client config. Also: README hero "See it in action" demo placement (ready to swap in a GIF; recording guide in web/docs-assets/README.md), Works-With table + exports + install docs updated, CHANGELOG Unreleased. package.json files/bin updated. Claude-Session: https://claude.ai/code/session_016JWn5jRD5tcEFKrubjQ6Px Co-authored-by: Claude <noreply@anthropic.com>
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trigger, description
| trigger | description |
|---|---|
| model_decision | Design statistically rigorous A/B tests and interpret experiment results. Use when asked to design an experiment, run an A/B test, calculate sample size, interpret test results, or assess whether an experiment was successful. Produces a complete experiment design with hypothesis, sample size, run time, success criteria, and risk flags — or a results interpretation with ship/iterate/kill recommendation. |
Experiment Designer Skill
Produce rigorous experiment designs from product hypotheses, and interpret results with statistical and practical significance — so you can defend every decision to a sceptical engineering lead or data scientist.
Required Inputs
Ask the user for these if not provided: For experiment design:
- Hypothesis (what change, what metric, what expected movement)
- Current baseline metric value
- Minimum detectable effect (MDE) — the smallest lift worth caring about
- Available daily sample size
For results interpretation:
- Control and variant results (raw numbers or percentages)
- P-value or confidence interval
- Run duration (days)
- Any anomalies observed during the test
Two-Phase Process
Phase 1: Experiment Design
- Restate hypothesis as: "If we [change], we expect [metric] to [move by X%] because [reason]"
- Define control and variant clearly
- Select primary metric (one only) and secondary guardrail metrics (2-3 max)
- Calculate required sample size from MDE and baseline
- Estimate run time in days
- Set pre-defined success criteria before the test runs — no moving goalposts
- Flag design risks: novelty effects, seasonal confounds, multiple testing issues, network effects, sample ratio mismatch
Phase 2: Results Interpretation
- Assess statistical significance (p < 0.05 threshold)
- Assess practical significance: was the lift meaningful for the business, not just real?
- Interpret confidence intervals
- Investigate confounding factors
- Recommend: Ship / Iterate / Kill / Run follow-up test
- Validate — Confirm the test ran for the full planned duration. Flag if it was stopped early (peeking problem). Confirm sample ratio mismatch did not occur.
Output Structure
[Design or Results header based on phase]
Hypothesis: "If we [change], we expect [metric] to [move by X%] because [reason]"
Primary metric: [One metric only] Guardrail metrics: [2-3 max] Required sample size: [n per variant] Estimated run time: [days] Pre-defined success threshold: [specific number] Design risk flags: [any concerns]
Results (Phase 2 only): Statistical significance: [p-value and conclusion] Practical significance: [lift size vs. business threshold] Recommendation: Ship / Iterate / Kill / Follow-up — [rationale]
Quality Checks
- Hypothesis specifies the change, the metric, the direction, and the reason
- Primary metric is singular — guardrail metrics are secondary
- Success criteria are defined before the test launches (not after seeing results)
- Test was not stopped early (or flagged clearly if it was)
- Practical significance assessed separately from statistical significance
- Sample ratio mismatch is checked in results interpretation
Anti-Patterns
- Do not define success criteria after seeing preliminary results — post-hoc success definitions are HARKing (Hypothesising After Results are Known) and invalidate the experiment
- Do not stop a test early because the result looks significant — early stopping dramatically inflates false positive rates; the test must run to the planned sample size
- Do not treat statistical significance as the same as practical significance — a p < 0.05 result with a 0.1% lift is real but may not be worth shipping
- Do not run the same experiment on the same population multiple times without correction — multiple testing inflates the chance of a false positive proportionally
- Do not use more than one primary metric — multiple primary metrics require multiple hypothesis corrections and make the ship/kill decision ambiguous