Describes three models for probabilistic indexing, all based on the Darmstadt automatic indexing approach, and presents experimental evaluation results for each. The discussion covers the improved retrieval effectiveness of probabilistic indexing over binary indexing, and suggestions for using this automatic indexing method with free text terms.…

A comparison of the effectiveness of information retrieval based on full-text documents with retrieval based on paragraphs, abstracts, or controlled vocabularies was accomplished using a subset of journal articles with nine search questions. It was found that full-text retrieval achieved significantly higher recall and lower precision than did the…

Describes a study of the retrieval results of World Wide Web search engines. Research quantified accurate matches versus matches of arguable quality for 200 subjects relevant to undergraduate curricula. Both "evaluative" engines (Magellan, Point Communications) and "nonevaluative" engines (Lycos, InfoSeek, AltaVista) were…

After reviewing the literature on automatic indexing research an experiment is described which examined term distribution and the effectiveness of the Two Poisson and Three Poisson Models in identifying good index terms. The conclusion reached is that these models should be applied with caution in document retrieval. (25 references) (EAM)

Briefly reviews early work in documentation and text processing, and predictions that were made about the creative role of computers in information retrieval. An attempt is made to explain why these predictions were not fulfilled and conclusions are drawn regarding the limits of computer power in text retrieval applications. (Author/CLB)

Describes a study that compared two information retrieval systems on a full-text medical database: one featured concept-based automatic indexing and statistical retrieval techniques, and the second used traditional word-based Boolean techniques. Evaluation of search results by calculating relative recall and precision is discussed, and user…

Discussion of index construction for large text collections highlights a new indexing algorithm designed to create large compressed inverted indexes "in situ." Topics include a computational model, inversion, index compression, merging, experimental test results, effect on retrieval performance, memory restrictions, and dynamic…

Suggests ways to increase precision when searching full text files on BRS, Mead Data Central and DIALOG. All of the techniques are based on achieving repetition of central concepts as expressed in natural language. Schematic representations of strategies and sample searches on each of the three systems are provided. (10 references) (CLB)

Grounded on object filtering, automatic indexing, and co-occurrence analysis, an experiment was performed using a parallel supercomputer to analyze over 400,000 abstracts in an INSPEC computer engineering collection. A user evaluation revealed that system-generated thesauri were better than the human-generated INSPEC subject thesaurus in concept…

Describes the advantages of a prototype retrieval system that uses statistically based ranked retrieval of records rather than traditional boolean methods, especially for end users. Several new techniques are also discussed including bit mapping, pruning, methods of building inverted files, and types of search engine. (26 references) (EAM)

Presents an approach to automatic matching and linkage of citations between databases which applied 14 coding techniques and measured their effectiveness in terms of efficiency of retrieval of duplicates with minimal false hits, reliability, and performance. (EAM)

Describes the use of a highly parallel array processor for pattern matching operations in a bibliographic retrieval system. The discussion covers the hardware and software features of the processor, the pattern matching algorithm used, and the results of experimental tests of the system. (37 references) (Author/CLB)

Examines the knowledge base of an intermediary expert system that provides advice about search term selection. Topics include a proposal for an integrated approach, including an option focusing on terminological attributes based on knowledge acquired from professional searchers; and the content of the knowledge base and the research needed to…

In World Wide Web indexing: (1) the creation process is automated; (2) the indexes are merely descriptive, not analytical of document content; (3) results may be sorted differently depending on the search engine; and (4) indexes link directly to the resources. This article compares the indexing methods and querying options of the search engines…

Reports on a study of index term selection techniques in a small experimental keyword information retrieval system. Two experiments are described which show that user success is improved by increasing the number of terms per object used. Implications for larger databases are considered. (22 references) (EAM)