THEORIES AND MODELS IN INFORMATION RETRIEVAL

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.

Theory and explanation in information retrieval research

The relationship between theory and explanation in informa tion retrieval research is analysed. Problems in the development of a generalisable information retrieval theory from informa tion retrieval experiment and the associated mathematical mod elling is examined. The source of these problems is traced back to assumptions underlying information retrieval research, and to the nature of the relationship between the theoretical frame work of information retrieval research and the nature of the problems on which this framework is brought to bear. Particu lar attention is directed to problems in measurement, in estab lishing a significant relationship between test results and results from operational evaluations, and in establishing a connection between the situational and behavioural assumptions employed in information retrieval research and real situations and be haviour.

The attempt to develop information retrieval research as an experimental science akin to natural science or engineering, around the notion of the quantification of relevance is miscon ceived. In order for information retrieval research to break out of the limitations of its present theoretical framework, and of the backwater to which that framework has led, a reorientation is required. The argument of this paper is that information retrieval research needs to be reoriented from a focus on the information retrieval system and on supposed 'systemic' factors to an orientation to the user and the user's interaction with information sources.

Informative Futures: Computer Simulation for Library Management

The megadimensional nature of the complex social systems of the twentieth century, and the increasing levels of interrelatedness, present the individual with a bewildering array of information sources and services.