In my last post, I discovered that the current problem datasets all suffered from an abundance of attribute values. Given that W acts on exact matching for it's query constraints, this causes a problem where nothing is left in the testing set after applying the first constraint. At least in the case of the ISBSG dataset, discretization makes a big difference:
Median Effort Reductions
Median Spread Reductions
For the Desharnais dataset, problems still remain. Even with discretization we can only generate a constrained query 25% of the time. The reported results use 9 discrete bins, but tinkering with this number has yet to see any gains in effort reduction. This is concerning, but currently all Desharnais projects are highly synthetic. A better look at the data is in order.