Cohort Analysis

Core Workflow

1. Identify question, cohort key, cohort start event, measurement window, metric, and segment.
2. Define inclusion/exclusion rules, data grain, time buckets, and censoring.
3. Separate cohort effects from calendar effects, seasonality, product changes, and acquisition mix.
4. Specify table/chart shape and comparison method.
5. Note data quality caveats and confidence level.
6. Convert findings into decision options or follow-up analysis.

Safety Rules

• Do not infer causality from cohort differences without supporting evidence.
• Do not invent cohort sizes, time windows, or source fields.
• Escalate analysis used for finance, investor reporting, compensation, compliance, or customer commitments.