Number of Examples to Use for Categorization
When preparing a categorization set in Relativity, don't be reluctant to use a lot of examples. Relativity suggests that a minimum of 5 to 20 documents be used for any one category, and that as many as 15,000 documents can be effectively used as examples for a single category.
There's no actual limit to the number of documents which can be used as examples for a category, but greater numbers of examples will slow down the categorization process. Relativity provides a general rule of thumb by noting that a workspace of a few million documents may require 2,000 example documents.