Cohort Analysis

Compare groups that share a start event over time to isolate lifecycle effects.

• How does retention differ by hire cohort?
• Did a policy change affect new hire outcomes?

• Clean employee event history
• Consistent definitions
• Adequate sample size

Group employees by start period or event; track a metric across subsequent intervals.

Compare 90-day retention for quarterly hire cohorts before and after onboarding redesign.

Parallel cohort trends suggest external factors; diverging trends suggest intervention impact.

Small cohort sizes; confounding when hiring profile changes between cohorts.