Domain Adaptation with Hierarchical Naive Bayes Classifiers by Bob Carpenter.
From the post:
This will be the first of two posts exploring hierarchical and multilevel classifiers. In this post, I’ll describe a hierarchical generalization of naive Bayes (what the NLP world calls a “generative” model). The next post will explore hierarchical logistic regression (called a “discriminative” or “log linear” or “max ent” model in NLP land).
Very entertaining and useful if you use NLP at all in your pre-topic map phase.