This system keeps the categories more straightforward,
and pretty well avoids the sort of subtle bias Wikipedia >has >been caught with
here. Defining the precise intersection of interest is up to the user.
But the corresponding weakness is that it depends on the editors hitting all the right
categories to work properly (as well as the tool itself, which as heavy toolserver users
know is not always the case). Someone may categorize in two of three but not the third
(guess which one might get forgotten?)
Daniel Case