This is a clearinghouse for a number of problems I've seen recently with the way we deal with subjects. Since changing stuff on this low level basically requires recalculating the presentation for every book on every site, we should try to get all the changes done at once.

• The default weight for an 'audience' or 'target age' classification that comes from an OPDS import (basically, the metadata wrangler) is 100. This made sense back when vendors didn't supply that information, but now it's way too high. It should be more like 1, the number we give other classifications from the metadata wrangler.

• The weight for any kind of classification that comes from Axis 360 is 1. This is way too low. It should be more like 100, the weight commonly used for classifications we get from Overdrive and Bibliotheca.

• We have an underlying assumption that a Dewey Decimal classification outside the "E" or "Y" range, or an LCC classification outside the "PZ" range, implies that a book is for grown-ups. It looks like this assumption doesn't hold in general – I've seen a children's book which OCLC Classify puts in what we think of as the "grown-up" section. If this assumption is, in fact, invalid, we need to change the behavior of those classifiers.