7. The method of claim 1 , further comprising repeatedly generating the updated probabilities that the categories of the taxonomy contain relevant documents based on the previous updated probabilities that the categories of the taxonomy contain relevant documents and re-determining the updated relevance of documents to the query.
7. The method of claim 1 , further comprising repeatedly generating the updated probabilities that the categories of the taxonomy contain relevant documents based on the previous updated probabilities that the categories of the taxonomy contain relevant documents and re-determining the updated relevance of documents to the query. 8. The method of claim 7 , wherein generating the updated probabilities that the categories of the taxonomy contain relevant documents ceases when a change in the updated probabilities is less than a convergence threshold.