Towards 'coring' and 'aboutness': an approach to some aspects of in-depth indexing
Some ideas about in-depth indexing are presented. Any document can be considered from two points: the core of the document which is usually one subject expressed by one term and the aboutness of the document which is usually many subjects expressed by several keywords and terms which may be either relative or non-relative to the core term. An experimental analysis with a sample of 100 petroleum documents using these new concepts appears to show that the terms unrelated to the core term must be reduced and the primary and minor relative terms need to be increased. The computing operation of the graduated aboutness is a way to weight the types of aboutness in in-depth indexing.