experiment-designer

experiment-designer is a cursor rule for Cursor from mohitagw15856/pm-claude-skills. It costs 75 tokens per session (876 once invoked), scanned A, original, MIT.

An experiment-planning guide for A/B tests, where two versions are compared to measure a change. It helps define the hypothesis, sample size, timing, metrics, and success criteria, then interpret the results.

In plain words
What is it for?
Use it to plan product experiments, calculate how many participants are needed, estimate test duration, and assess whether results are both statistically and practically meaningful.
Why use it?
It prevents teams from changing goals during a test or mistaking random variation for a real improvement. It also highlights issues such as seasonal effects and novelty effects.

Cursor rule for Cursor

Written for Cursor: a Cursor rule (.mdc).

Good fit Use it to plan product experiments, calculate how many participants are needed, estimate test duration, and assess whether results are both statistically and practically meaningful.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/mohitagw15856/pm-claude-skills/experiment-designer
About the project

PM Skills is a collection of plain-Markdown instructions that teach AI assistants structured methods for handling professional, personal, and life-admin tasks. People use it with Claude, ChatGPT, Gemini, Cursor, Codex, and other supported agents for work such as writing product requirements, reviewing documents, or planning difficult situations.

mohitagw15856/pm-claude-skills · 1,357 stars · on GitHub · mohitagw15856.github.io

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/mohitagw15856/pm-claude-skills

Made for: Cursor.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for experiment-designer

README.md
[![agentmods](https://agentmods.dev/badge/rules/mohitagw15856/pm-claude-skills/experiment-designer/github.svg)](https://agentmods.dev/rules/mohitagw15856/pm-claude-skills/experiment-designer)
Your own site
<a href="https://agentmods.dev/rules/mohitagw15856/pm-claude-skills/experiment-designer"><img src="https://agentmods.dev/badge/rules/mohitagw15856/pm-claude-skills/experiment-designer/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for experiment-designer

Your own site · 80×15
<a href="https://agentmods.dev/rules/mohitagw15856/pm-claude-skills/experiment-designer"><img src="https://agentmods.dev/badge/rules/mohitagw15856/pm-claude-skills/experiment-designer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 75 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 876 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00075 $0.00876
Opus 5 $0.00037 $0.00438
Sonnet 5 $0.00015 $0.00175
Haiku 4.5 $0.00007 $0.00088

Measured 9d ago against content hash 562cda638334, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

experiment-designer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

exports/cursor/pm-advanced/experiment-designer/experiment-designer.mdc · 79 lines

How it starts

The opening of the file, as written. The whole thing — 79 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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

  1. Restate hypothesis as: "If we [change], we expect [metric] to [move by X%] because [reason]"
  2. Define control and variant clearly
  3. Select primary metric (one only) and secondary guardrail metrics (2-3 max)
  4. Calculate required sample size from MDE and baseline
  5. Estimate run time in days
  6. Set pre-defined success criteria before the test runs — no moving goalposts
  7. Flag design risks: novelty effects, seasonal confounds, multiple testing issues, network effects, sample ratio mismatch

Phase 2: Results Interpretation

  1. Assess statistical significance (p < 0.05 threshold)
  2. Assess practical significance: was the lift meaningful for the business, not just real?
  3. Interpret confidence intervals
  4. Investigate confounding factors
  5. Recommend: Ship / Iterate / Kill / Run follow-up test
  6. 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]

Read the full file on GitHub · 79 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 79 lines · 75 tokens per session scan A 562cda638334

Subscribe to this mod's changes

experiment-designer is a cursor rule published in the GitHub repository mohitagw15856/pm-claude-skills (1,357 stars, last pushed yesterday), licensed MIT. It adds 75 tokens to every session and 876 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.