experiment

# Experiment > PREREQUISITE: Read `../_mureo-shared/SKILL.md` for auth, security rules, output format, and **Tool Selection** (Read/Write on Code, `mureo_strategy_*` / `mureo_state_*` MCP on Desktop / Cowork). Turn an ad-hoc change into a **designed experiment**. Most "we tried X and CPA moved" claims are noise — one variable was never isolated, the window was never fixed, and the decision was made by peeking. This skill enforces the discipline: a falsifiable hypothesis, exactly **one** variable, a success metric tied to a Goal, a pre-committed duration and sample floor, no peeking, and a per-variant verdict where **inconclusive is a valid outcome**. Read `../_mureo-learning/SKILL.md` first — its **Observation Windows** and **Minimum Sample Sizes** tables set the duration and sample floor this skill commits to, and its evidence lifecycle is the rulebook for the no-peeking rule below. ## Prerequisites - STRATEGY.md and STATE.json must exist (run the `onboard` skill first) ## Steps **Before you start**: Run the **Diagnostic preamble** from ../_mureo-shared/SKILL.md — load learning insights (mureo_learning_insights_get) and consult advisors (mureo_consult_advisor) before drawing conclusions. 0. **Establish today**: call `mureo_state_get` **first, on every host** (including Claude Code, where you would otherwise `Read` the file) and take `server_now` from its response — ISO 8601 with UTC offset, e.g. `2026-07-28T10:12:33+09:00`. Its date is the **only source of the current...