P100PandasIntermediateInterpret12 min
Interpret a Cohort Retention Table With Changing Denominators
Interpret retention percentages when cohorts have different initial sizes and incomplete later periods.
#interpret#cohorts#retention
Scenario
A retention table reports users retained relative to each cohort's original signup count. January has 1,000 signups and February has 200; February's month-3 observation is not yet complete.
Problem statement
Interpret the table, choose denominators, and explain why raw retained counts and incomplete periods can mislead.
Your Task
- Define what each retention percentage represents.
- Compare rates using each cohort's initial size.
- Flag incomplete observation windows and avoid causal claims.
Cohort table
Cohort Size Month 1 Month 2 Month 3
January 1,000 600 (60%) 450 (45%) 390 (39%)
February 200 140 (70%) 86 (43%) 30 (15%, partial)
Related Concepts
Cohort analysisRetentionDenominators
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