Free practice · matching · hard

Practice

Match population risks to controls

Match each population risk to the control that addresses it.

Population contract

Every filter must be explicit enough to reproduce

Region
Northeast
Status
Completed under one approved definition
Window
>= Aug 1 and < Sep 1, 2026
Measure
Sum completed-order revenue in USD

Closed-open time boundaries prevent overlap at midnight, while a filter waterfall keeps denominator changes visible.

Match each item