14. The computer-readable medium of claim 13 wherein the item selection field contained by the index entry for the distinguished item contains, for each of a plurality of terms, a number of occurrences of the term that reflects the frequency with which users select the distinguished item from search results produced by the search engine in response to queries containing the term.
13. The computer-readable medium of claim 12 wherein the updating comprises adding the distinguished query term to the contents of an item selection field contained by the index entry for the distinguished item.