Cohort Analysis

Overview

Cohort Analysis answers "are we retaining users better than last quarter?" by measuring N-day, weekly, or monthly retention, comparing acquisition cohorts, or pinpointing the period where users typically churn.

What it covers

• Defines the cohort grouping (signup month, first purchase date) and the retention event (login, purchase, feature use).
• Builds a cohort by period membership table from event data.
• Computes the full retention matrix, period over period, for every cohort.
• Renders a heatmap of the retention matrix plus a time series of retention curves per cohort.
• Writes a narrative report interpreting the figures using a retention metrics glossary for consistent definitions.

Part of Data Analytics Skills

This is one of 31 skills in the Data Analytics Skills library, in the Data Analysis & Investigation group.

Installation

1. Clone the repo once: git clone https://github.com/nimrodfisher/data-analytics-skills.git
2. Copy just this skill: cp -r data-analytics-skills/03-data-analysis-investigation/cohort-analysis ~/.claude/skills/ (or ~/.agents/skills/ for Codex)
3. Ask your agent something like "how does retention differ across our signup cohorts this year" and it activates on its own.

See the Data Analytics Skills entry for the full library.