What is a cohort analysis and when would you use it?
Model answer
Model answerA cohort analysis groups users by a shared characteristic — usually the time they signed up — and tracks their behavior over time. You use it when aggregate metrics are hiding the truth. If overall retention looks flat but cohorts from 6 months ago retain at 60% while recent cohorts retain at 30%, you have a serious problem that averages conceal. I'd use cohort analysis whenever I suspect that product quality or user quality has changed over time.
Framework · Cohort Analysis
- ADefine the cohort
Pick the right cut: signup date, acquisition channel, or feature adoption - RChoose the metric
What behavior to track: retention, revenue, or engagement — per cohort - RCompare across time
Do newer cohorts perform better or worse? Plot the curves and look for trends - RDiagnose the gap
If a cohort dips, what changed? Feature launch? Marketing channel? Seasonality?
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