1. A medium storing instructions executable by at least one processor, the instructions configured to cause the at least one processor to: create a search query comprised of at least one term in a specific document; apply the search query to a collection of documents; select from the collection of documents a subset of documents, the subset of documents achieving the highest scores upon application of the search query; select at least one term for use as at least one index term for the specific document from among terms in the subset of documents based upon the co-occurrence of terms in the subset of documents with terms in the specific document.