A comparative evaluation of results in terms of recall and precision from queries submitted to systems with automatic and manual subject indexing. Differences were attributed to query formulation. The effectiveness of automatic indexing was found equivalent to manual indexing. (Author/KP)

This report summarizes the work carried out on the automatic construction of keyword classifications and their use in information retrieval. It discusses the possible characteristics of such classifications, and potential ways of using them; and describes the various approaches to classification that were considered in terms of an overall frame of…

Compares the retrieval performance of a technique for machine-aided indexing using a controlled vocabulary with that of a Key Word Out of Context Index, basing conclusions on the results of 20 subject searches of a database containing summaries of defense management data. (FM)

The development of an automatic indexing technique, called Double KWIC (DKWIC) Coordinate Indexing, is described which extends the KWIC indexing principles to provide easy access to an additional level of specificity for information indexed under these frequently appearing terms. Chapter 2 discusses indexing terminology and some fundamental…

Investigates the feasibility of using a distance measure for automatic sequential document classification. This property of the distance measure is used to design a sequential classification algorithm which classifies key words and analyzes them separately in order to assign primary and secondary classes to a document. (VT)

Presents adaptation of a probabilistic theoretical model previously used in relevance feedback for use in automatic indexing of documents (in the sense of imitating) human indexers. Methods for model application are proposed, independence assumptions used in the model are interpreted, and the probability of a dependence model is discussed.…

The substitution information contained in automatically obtained keyword classification is most effectively exploited when: (1) strong similarity connectives only are utilized, (2) grouping is confined to non-frequent terms, (3) term groups are used to provide additional and not alternative descriptive items and (4) descriptor collection frequency…

Reviews major term-weighting theories, presents methods for estimating the relevance properties of terms based on their frequency characteristics in a document collection, and compares weighting systems using term relevance properties with more conventional frequency-based methodologies. Eighteen references are cited. (Author/FM)

Analyzes a study of the effect of controlled variations in indexing vocabulary size on retrieval performance, using the Cranfield 200 and 1400 test collections. Sets of variable-length character strings were tested, in an application of the Cluster Hypothesis and in a series of linear associative retrieval experiments. (Author/SW)

Empirical significance of document partitions is investigated as a function of index term-weight and similarity thresholds. Results show the same empirically preferred partitions can be detected by two independent strategies: an analysis of cluster-based retrieval analysis and an analysis of regularities in the underlying structure of the document…

Describes research designed to improve automatic pre-coordinate term indexing by applying language analysis techniques to identify term sources in requests, and to generate variant expressions of concepts involved for document text searching. Text analysis, term extraction, variant generation, and retrieval trial are highlighted. Thirteen…

A report of several comparisons designed to measure the retrieval effectiveness of machined-aided indexing and manual indexing. (Author)

Substantial alterations to a system often have little or no effect on particular collections. This may be due to poor separation of relevant and non-relevant documents. The paper presents a procedure for characterizing this separation, which can show whether proposed modifications of the base system are likely to be useful. (8 references)…

Retrieval performance with automatic term classifications for three test collections has been variable. This paper attempts to discover why. The real difference between the collections is in the separation of relevant from non-relevant documents. The separation is so poor that classification cannot be expected to succeed. (14 references)…

Discussion of automatic indexing in information retrieval systems focuses on attempts to improve the indexing representation produced by the FASIT system. Concept selection and concept grouping are explained; improving disambiguation is discussed; and a retrieval experiment to test the effectiveness of the disambiguation using the cystic fibrosis…