tailieunhanh - Báo cáo khoa học: "Applications of the Theory of Clumps"

[, , and 4, June and October 1965] * by , Cambridge Language Research Unit, Cambridge, England The paper describes how the need for automatic aids to classification arose in a manual experiment in information retrieval. It goes on to discuss the problems of automatic classification in general, and to consider various methods that have been proposed. The definition of a particular kind of class, or "clump," is then put forward. Some programming techniques are indicated, and the paper concludes with a discussion of the difficulties of adequately evaluating the results of any automatic classification procedure. The . Information Retrieval Experiment Since the. | Mechanical Translation and Computational Linguistics and 4 June and October 1965 Applications of the Theory of Clumps by R. M. Needham Cambridge Language Research Unit Cambridge England The paper describes how the need for automatic aids to classification arose in a manual experiment in information retrieval. It goes on to discuss the problems of automatic classification in general and to consider various methods that have been proposed. The definition of a particular kind of class or clump is then put forward. Some programming techniques are indicated and the paper concludes with a discussion of the difficulties of adequately evaluating the results of any automatic classification procedure. The . Information Retrieval Experiment Since the work on classification and grouping now being carried out at the . arose out of the Unit s original information retrieval experiment I shall describe this experiment briefly. The Unit s approach represented an attempt to combine descriptors and uniterms. Documents in the Unit s research library of offprints were indexed by their most important terms or keywords and these were then arranged in a multiple lattice hierarchy. The inclusion relation in this system was interpreted very informally as follows term A includes term B if when you ask for a document containing A you do not mind getting one containing B. A particular term could be subsumed under as many others as seemed appropriate so that the system contained meets as well as joins that is was a lattice as opposed to a tree for example as follows The system was realized using punched cards. There was a card per term with the accession numbers of the documents containing the term punched on it at the right hand side of the card were the numbers of This document is based on lectures given at the Linguistic Research Center of the University of Texas and elsewhere in the United States in the spring of 1963. It is intended as a general reference work on