Today's Search Term: Term Density

'Term density' is a calculated percentage of how frequently a term appears in a document, relative to the overall size of the document. This fixes the problem with simple term frequency calculations. For example, if a word appears 5 times in a 2 page document and 10 times in document a 100 page document, the first document is probably still more relevant, even though it has 5 less occurrences of the term.

From the New Idea Engineering Glossary of Search-Related Terms