UA Ledger · Measurement Lab · draft for review

Put a Wilson interval beside a small retention estimate

Synthetic teaching inputs. No real campaign results or industry defaults. Change the values to inspect the model. Calculations run locally; this page sends no data and does not retain inputs after closing.

Count one eligible return outcome per independent install and preserve the total sample. The score-interval formula adjusts the centre and width using the sample size, observed proportion and squared quantile. The supplied artifact shows the arithmetic rather than rounding a small cohort to a confident whole percentage. For clustered or dependent observations, this model is not the correct uncertainty calculation.

Calculated outputs

Assumption sensitivity

Only n varies; all other inputs are held constant. This is not a probability range.

Equations

Additional constraints: (x<=n). The field minimums also apply.

Limits

Use a pre-specified analysis plan for comparisons or repeated monitoring. Overlapping or non-overlapping intervals alone are not a complete test of the difference between two campaign treatments.

Confidence intervals for a proportion · primary documentation checked 19 September 2026.