A method and apparatus to identify names, personalities, titles, and topics that are present in a repository and to identify names, personalities, titles, and topics that are not present in the repository, uses information from external data sources, notably the text used in non-speech, text-based searches, to expand the search terms. The expansion takes place in two forms: (1) finding plausible linguistic variants of existing search terms that are already comprehended in the repository, but that are present under slightly different names; and (2) expanding the existing search term list with items that should be there by virtue of their currency in popular culture, but which for whatever reason have not yet been reflected with content items in the repository.