Access to nonbook materials: the limits of subject indexing for visual and aural languages

An examination of some nonbook materials with respect to an aboutness model of indexing leads to the conclusion that there are instances that defy subject indexing. These occur not so much because of the nature of the medium per se but because it is being used for nondocumentary purposes, or, where being used for such purposes, the subject referenced is nonlexical. © 1994 John Wiley & Sons, Inc.