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Willett, Peter | 8 |
El-Hamdouchi, Abdelmoula | 1 |
Pogue, Christine | 1 |
Popovic, Mirko | 1 |
Robertson, Alexander M. | 1 |
Stewart, Mark | 1 |
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Journal Articles | 8 |
Reports - Research | 7 |
Information Analyses | 1 |
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Reports - Evaluative | 1 |
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El-Hamdouchi, Abdelmoula; Willett, Peter – Information Processing and Management, 1988
Describes an algorithm for the calculation of term discrimination values that may be used when the interdocument similarity measure used is the cosine coefficient and when the document representations have been weighted using one particular term weighting scheme. (7 references) (Author/CLB)
Descriptors: Algorithms, Automatic Indexing, Computational Linguistics, Discriminant Analysis

Robertson, Alexander M.; Willett, Peter – Journal of Documentation, 1996
Describes a genetic algorithm (GA) that assigns weights to query terms in a ranked-output document retrieval system. Experiments showed the GA often found weights slightly superior to those produced by deterministic weighting (F4). Many times, however, the two methods gave the same results and sometimes the F4 results were superior, indicating…
Descriptors: Algorithms, Comparative Analysis, Information Retrieval, Online Searching

Stewart, Mark; Willett, Peter – Journal of Documentation, 1987
Describes the simulation of a nearest neighbor searching algorithm for document retrieval using a pool of microprocessors. Three techniques are described which allow parallel searching of a binary search tree as well as a PASCAL-based system, PASSIM, which can simulate these techniques. Fifty-six references are provided. (Author/LRW)
Descriptors: Algorithms, Computer Simulation, Correlation, Documentation

Willett, Peter – Information Processing and Management, 1988
Reviews recent research into the use of hierarchic agglomerative clustering methods for document retrieval. The topics discussed include the calculation of interdocument similarities, algorithms used to implement clustering methods on large databases, validity testing of document hierarchies, appropriate search strategies, and other applications…
Descriptors: Algorithms, Bibliometrics, Cluster Analysis, Comparative Analysis

Popovic, Mirko; Willett, Peter – Journal of the American Society for Information Science, 1992
Reports on the use of stemming for Slovene language documents and queries in free-text retrieval systems and demonstrates that an appropriate stemming algorithm results in an increase in retrieval effectiveness when compared with nonstemming processing. A comparison is made with stemming of English versions of the same documents and queries. (24…
Descriptors: Algorithms, Comparative Analysis, English, Full Text Databases

Willett, Peter – Information Processing and Management, 1985
Reports algorithm for calculation of term discrimination values that is sufficiently fast in operation to permit use of exact values. Evidence is presented to show that relationship between term discrimination and term frequency is crucially dependent upon type of inter-document similarity measure used for calculation of discrimination values. (13…
Descriptors: Algorithms, Graphs, Information Retrieval, Information Systems

Willett, Peter – Information Processing and Management, 1981
Describes a fast algorithm for comparing the lists of terms representing documents in automatic classification experiments. Complexity and running time for the algorithm are compared to other procedures, and a short algol-like routine is presented in the appendix. Eight references are included. (Author/BK)
Descriptors: Algorithms, Automatic Indexing, Classification, Documentation

Pogue, Christine; Willett, Peter – Online Review, 1984
Describes preliminary investigation of the use of International Computers Limited's Distributed Array Processor (DAP) for parallel searching of large serial files of documents. DAP hardware and software, test collections, measurement of DAP performance, search algorithms, experimental results, and DAP suitability for interactive searching are…
Descriptors: Algorithms, Comparative Analysis, Computer Software, Digital Computers