Keyword stuffing in the Title Tag is looked at as search engine spam (not good). But it might be smart to repeat the same word in different ways.

For example, if you build an application to sell video tapes, you might expect a user to query for all the videos that have a certain keyword in the title and that were directed by a given person.

The dimension tables describe each analysis entry in the fact table: the actual date, the keyword values and categories as well as corresponding document title and content.