Some parameters and techniques in use for describing the results of tests on IR systems are analysed. Several considerations outside the scope of the usual 2 x 2 table are…
Abstract
Some parameters and techniques in use for describing the results of tests on IR systems are analysed. Several considerations outside the scope of the usual 2 x 2 table are relevant to the choice of parameters. In particular, a variable which produces a ‘performance curve’ of a system corresponds to an extension of the 2 x 2 table. Also, the statistical relationships between parameters are all‐important. It is considered that precision is not such a useful measure of performance (in conjunction with recall) as fallout. A more powerful alternative to Cleverdon's ‘inevitable inverse relationship between recall and precision’ is proposed and justified, namely that the recall‐fallout graph is convex.
The search for an easily installed, practicable and inexpensive information retrieval system continues unabated. This is reflected in the Aslib Library almost daily by requests…
Abstract
The search for an easily installed, practicable and inexpensive information retrieval system continues unabated. This is reflected in the Aslib Library almost daily by requests for advice on the feasibility of installing this or that system, or for information on what systems are available in Great Britain. Study of the following bibliography, which covers only a narrow selection of information retrieval systems, will reveal that much original thought has been producing concrete results in this country. In fact, one of the earliest references is to a paper given at the twenty‐second Aslib Conference in 1947 by W. E. Batten, in which he describes his development of an ‘aspect’ card system—more often referred to today as ‘Peek‐a‐boo’ or ‘feature’ cards. Mr C. W. Cleverdon's Cranfield project is also adding considerable knowledge on the use of various indexing methods, including Uniterm.
Methods of testing systems in practice and in theory are critically reviewed. Some new theoretical considerations are advanced.
The last CRG Bulletin, no. 7, dealt only with the practical application of four faceted special classifications.
The investigation dealt with the effect which different devices have on the performance of index languages. It appeared that the most important consideration was the specificity…
Abstract
The investigation dealt with the effect which different devices have on the performance of index languages. It appeared that the most important consideration was the specificity of the index terms; within the context of the conditions existing in this test, single‐word terms were more effective than concept terms or a controlled vocabulary.
C.W. CLEVERDON and L.J. HARPER
There are several reasons for thinking that special librarianship today is at a most interesting but also most serious and even critical stage. The life of Aslib, which one may…
Abstract
There are several reasons for thinking that special librarianship today is at a most interesting but also most serious and even critical stage. The life of Aslib, which one may reasonably say covers the life of special librarianship in this country, can be divided into two parts: from its commencement in 1924 until the beginning of the second world war, and from then until the present day. It may be somewhat arbitrary to make a particular date the dividing line, for the two periods merged into each other, but looking back it is possible to argue that the date 1939 was important. Equally so, it appears that we are now entering a new era in special librarianship, and that in, say, 1980 it will be possible to say that some time around now was a definite turning point. Whether the comments in 1980 are that there was a moving forward or a moving backward will depend on our actions in the immediate future.
While Fairthorne may not have been the first person to recognize it, certainly, for this author, Fairthorne was the first to make explicit the fundamental problems of information…
Abstract
While Fairthorne may not have been the first person to recognize it, certainly, for this author, Fairthorne was the first to make explicit the fundamental problems of information retrieval systems, namely the clash between OBNA and ABNO (Only‐But‐Not‐All and All‐But‐Not‐Only). Although it was not until 1958 that the terms occur in Fairthorne's writings, the concept had been discussed in many meetings of the AGARD Documentation Panel and elsewhere. Originally it was considered that to meet these two requirements, it might be necessary to have two separate systems, and the test of the UNITERM system in 1954 was based on the hypothesis that a ‘Marshalling’ system (e.g. U.D.C.) was fundamentally different from a ‘Retrieval’ system (e.g. UNITERM). While the idea persisted in this form for some time, it gradually evolved into the inverse relationship of recall and precision, which is to say that while it is possible to obtain, of the relevant documents, All‐But‐Not‐Only, or alternatively to obtain Only‐But‐Not‐All, it is not possible to obtain All and Only.
This article reviews the state of the art in automatic indexing, that is, automatic techniques for analysing and characterising documents, for manipulating their descriptions in…
Abstract
This article reviews the state of the art in automatic indexing, that is, automatic techniques for analysing and characterising documents, for manipulating their descriptions in searching, and for generating the index language used for these purposes. It concentrates on the literature from 1968 to 1973. Section I defines the topic and its context. Sections II and III consider work in syntax and semantics respectively in detail. Section IV comments on ‘indirect’ indexing. Section V briefly surveys operating mechanized systems. In Section VI major experiments in automatic indexing are reviewed, and Section VII attempts an overall conclusion on the current state of automatic indexing techniques.
Dear Madam, In his article ‘Automation in indexing’, published in Aslib Proceedings, vol. 13, no. 4 (1961), pp. 107–9, C. W. Cleverdon erred in his description of the indexing…
Abstract
Dear Madam, In his article ‘Automation in indexing’, published in Aslib Proceedings, vol. 13, no. 4 (1961), pp. 107–9, C. W. Cleverdon erred in his description of the indexing technique used in the preparation of Chemical Titles. The keywords are not selected in advance from a prepared list. Instead all words not to be indexed form the list given to the computer.
The 54th meeting of the CRG was held at the College of Aeronautics, Cranfield, where the Aslib Research Project is testing the comparative efficiency of information retrieval…
Abstract
The 54th meeting of the CRG was held at the College of Aeronautics, Cranfield, where the Aslib Research Project is testing the comparative efficiency of information retrieval systems. One system on trial is a faceted classification for Aeronautics and allied subjects, drafted by B. C. Vickery and J. E. L. Farradane, and since revised with the aid of the Project workers, C. W. Cleverdon, J. Hadlow, T. Opatowski, and J. Sharp.