Proceedings of the International Conference on Scientific Information Two Volumes (1959) / Chapter Skim
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The Evaluation of Systems Used in Retrieval Systems on Large Electronic Computers
The Evaluation of Systems Used in Retrieval Systems on Large Electronic Computers
Pages 687-698
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From page 687... ...
Any system can, if economic aspects be disregarded, reach a high level of retrieval efficiency, even if it involves looking at the majority of individual documents in the collection, and the important matter is to find which system will give the required level of efficiency at the lowest cost. It is useless to attempt to compare any two established indexes unless one also has reliable data concerning their compilation costs.
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From page 688... ...
the Universal Decimal Classification, (2) an alphabetical subject catalogue, based on the Special libraries Association "Subject headings for aeronautical engineering libraries," (3)
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From page 689... ...
Whereas one very vocal school of thought insists that technical indexing can be done only by a person with technical qualifications, there are others who argue that this is untrue, and that anyhow it would be wasteful to employ technical persons on such work. However, no results are known oftests designed to compare the average indexing ability of different types of persons.
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From page 690... ...
Few reliable figures have been given for current practices, although a particularly high figure is the 13< hours average quoted (2) for indexing reports for the catalogue of aerodynamic data prepared by the Nationaalluchtvaartlaboratorium in Holland.
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From page 691... ...
. the documents should cleat with the specialised subject field of high-speed aerodynamics while the remainder range over the broader subject fields.
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From page 692... ...
~ ~ ~ ~ . sing would be made in the various catalogues, with an identification mark so that it will be possible to find in the testing whether these entries give better retrieval than the entries of the project's indexers The test programme Although the main testing will not be done until the indexing work has been completed towards the end of 1959, it is hoped that some preliminary testing will be possible In time to present the results at the International Conference.
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From page 693... ...
As stated earlier, the retrieval cost must include not only the time costs in searching the index but also the time costs involved in making physically available the required document. This latter item is a figure which will vary with each individual organisation and will have to be built into the results.
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From page 694... ...
Analysis of tests With so many variables being introduced into the indexing and the retrieving, there will be many differing answers given by the results, and it is unlikely, to say the least, that one system will be preeminent irrespective of the conditions. The test results will be a set of objective statements showing what has been achieved under the differing conditions, and it will be for each organisation to
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From page 695... ...
With very few exceptions, such as patent ounces, which, by the nature of their work, will have a complete file of a certain type of recorded material, the large majority of organisations concerned with science or technology do not have in their collections more than a small fraction of the potentially available information in all aspects of the organisation's work. Within strictly limited subject fields, it is possible that a librarian might manage to collect 50~0 of the potentially available documents, but it will require extensive and prolonged searching to raise the figures over 80%.
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From page 696... ...
Most organisations issuing aeronautical reports include with each document, catalogue cards showing the subject headings or classification numbers for the report. An analysis of these cards shows that on average about 4 placings are given to each report, while less than To are given more than eight placings.
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From page 697... ...
For this purpose, the indexers wid be instructed to enter on the master cards ah subject headings or class numbers which they consider in any way suitable, but-they wiD place a mark against those which are considered to be essential and which would be allocated in normal practice. Such entries wiD be identified in the card catalogues, and in the testing it Win be possible to find whether the additional entries are justified by reason of improved retrieval, or whether they clutter up the catalogue and are positively harmful by increasing the number of irrelevant answers.
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From page 698... ...
(R.A.E. Library Memo 7)
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