It is intended to include all important reference works and a wide selection of specialized monographs, as well as a very extensive collection of journals and major indexing and abstracting services in the field. Pertinent foreign language materials are included. Older material is usually retained for historical research and actively preserved. A collection at this level supports doctoral and other original research. A comprehensive level collection may serve as a national or international resource.
Older material is retained for historical research with active preservation efforts.
Defined access means more than simply providing patrons with access to the Internet and one or more Internet browsers. Defined access refers to menu options on the library or institution's home page, etc., which link the user to owned or remotely accessed electronic resources selected by the library with the needs of its patrons in mind. The level of defined access changes according to the level of the collection, e.g., from limited to extensive to very extensive access to collections of electronic information.