Hi there,
In working through the Udacity assignment on AB testing (again, thank you @PatrickN ), it seems that there's no obvious way to use location directly as a distance factor for selecting control units.
Additionally - the identifier field for a unit has to be a character field.
It seems that here would be a lot of value in making 2 changes to this tool:
a) allowing for integer unit identifiers (like store ID - not sure why a character is required)
b) using an actual point (location) to determine closest potential control unit.
- This is particularly important in the US where two towns may be very close to each other although they are in different states
- So the actual distance on the earth's surface would be a better indicator of closeness between test & control units than state or county.