130 Book reviews

carried out by a broker. The directory also provides raw data for those concerned with the history of online searching in the UK.

A new edition or a regular updating of this directory would be most welcome.

F. E. Wood Department of Information Studies Uniuersity of Shefjeld

John Williamson and Bob Raggett. Teletex. London: Eurodata Foundation, 1982. (Eurodata Foundation Guides for Managers). 69 pp. ISBN not given. E8.50.

It is curious that an organization devoted to the transfer of information should have such a cavalier attitude towards standard publishing practice: not only does this document lack an ISBN but the authors’ names do not appear on the title page. The first indication that the pamphlet is written by humans does not appear until page 9!

However, apart from these slight curiosities, what of the text? This is a timely introduction to one of those confusingly-named communication technology developments. Not ‘teletext’, nor even ‘Telex’ (although that comes close), but ‘Teletex’pa text communication service which, in all probability, will ultimately replace Telex. Not a set of equipment, as the authors point out, but:

. . a series of specifications which, if adhered to, will ensure compatibility between any manufacturer’s terminals for high speed exchange of alpha numeric information.’

The specifications referred to are those embodied in draft standards of the CCITT (Gomite Consultatif International Telegraphique et Telephonique) which specify basic terminal types, memory characteristics, message format, call identification, and transmission speed. This last element indicates why Teletex will replace Telex: the transmission speed of Teletex is 2400 bits per second, 30 times faster than Telex. Telex terminals are likely to survive for quite a long time, however, because interconnection with Teletex is possible.

After a brief introduction to the technical specifications the authors go on to describe the role of Teletex in office communications, its relationship to alternatives such as letter post, facsimile transmission, and computer mail (sometimes called ‘electronic mailbox’), network alternatives, PTT services, Teletex terminals, costs, impact on other services, case studies, and future developments. Each chapter is brief, well written, and designed for the target audience.

In all, this will be a useful little guide for managers and the price of L8.50 is not likely to be a deterrent in that market.

TDW

Thesaurus of ERIC descriptors (9th edn). Oryx Press, 1982. 569 pp. ISBN 0 89774 019 X. 922. J. Aitchison in association with 1. A. Smith and S. Thompson, (Compilers). An integrated classz$cation and thesaurus for youth ajfairs and related topics. National Youth Bureau, 1981. 530 pp. ISBN 0 86155 044 7. k50.

These two substantial thesauri are powerful expressions of the traditional belief

Book reviews 131

in the efficacy of controlled and structured vocabularies for the subject retrieval of documents. In the case of ERIC this belief has been held with a tenacity that has little to do with practical success. The inadequacies of the earlier editions of the ERIC Thesaurus are well enough known. The immense effort invested in the massive, and unparalleled, revision of the 8th edition in 1980 is unconditional acknowledgement of the failures of past policies. The current edition, like its immediate predecessor, reflects a new approach intended to improve both the quality of indexing and assistance given to searchers. There is every reason to believe that the compilers have achieved their aims.

ERIC produced the first of the major thesauri in the social sciences in 1967. Despite the accretion of more or less helpful display devices in the intervening period the Thesaurus remains an example of the first generation of such retrieval tools. The main section consists of an alphabetical list of acceptable and non- acceptable index terms. The main section is supplemented with a rotated display of descriptors, descriptor groups and a two-way hierarchical display of terms. From the outset the ERIC compilers regarded the terminologies of the social sciences as creating problems largely unknown in the sciences and technologies. In the main this awareness of different linguistic conventions shaped practical responses in two ways. Numerous multi-word index terms were allowed in the thesaurus in an effort to cope with conceptual complexities and the noted imprecision arising from the coordination of single word terms; the ‘looseness’ of social science terminologies was allowed for through the generous provision of ‘use/use for’ references and lavish (over-lavish?) provision of ‘related terms’. Curiously, until the 8th edition, the latter problem of matching words to concepts did not produce a thesaurus replete with definitional scope notes. It was assumed, without much supporting evidence, that the meaning of an index term would be made clear by the contextual, or locating, information provided by the associated BTs, NTs and RTs. This practice (not confined to the ERIC Thesaurus) was not conducive to effective retrieval within the labyrinthine networks created through the non-standard usages of words by social scientists. The 8th and 9th editions of the thesaurus have recognized the absurdity of past policy on this matter and now provide scope notes in abundance. The extent of the change is significant. Whereas the 1967 ERIC Thesaurus had 1 scope note for every 25 index terms the current edition has a scope note for every 2 index terms. Such changes are to be welcomed.

The Thesaurus on youth exemplifies the development of the thesaural idea away from the conventions embodied in the ERIC Thesaurus. Its main sequence is classified and, unlike the latter, ‘is designed to give browsability on the shelves and in the catalogue’ and ‘to operate in either a manual or computerised situation’. The reluctance ofBritish and Continental retrievalists to discard the predetermined structures of classification has been powerful enough to ensure the replacement of the main alphabetical sequence by classified schedules. There is insufficient evidence to suggest that this method is any better, or worse, than the simpler layouts and philosophies of the ‘traditional’ thesauri. To this reviewer the thesaurofacet form, and that of its descendants, of which the Thesaurus on youth is avowedly one, seem better designed for use by information intermediaries rather than end-users.

Inevitably, the compilers of Thesaurus on youth have had to frame a policy for the treatment of compound terms and levels of pre-coordination. By and large the recommendations of British Standard 5723:1979 have been adopted. The informative introduction makes clear the point and purpose of deviations from

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the Standard as well as explaining the general reasoning and conventions of the thesaurus. In technical terms there is no doubt that this is a thesaurus ofquality exhibiting a more apparent systematic approach to the task of thesaurus construction than is evident in the history of the ERIC irhesaurus.

The form of this review is indicative of the difficulty faced by reviewers of practical compilations such as thesauri. Testing is more appropriate than reviewing for such tools. It is a pity that the profession appears to have lost interest in the practical testing of practical tools of the trade. A state of affairs that condemns us to generalize from the esoteric experimental experiences of a few researchers and repeatedly wonder why we still know so little about the information behaviour of real users of real systems.

Norman Roberts

ERRATA

Vol 3 No 1 January 1983

CONTRACT RESEARCHERS’ PROBLEMS AND THE COMMUNICATION OF FINDINGS TO THEIR SPONSORS

M. D. GORDON

p. 11 (Table 2). In the column headed Universities and rows (g), (i), (i) and (k) where the values 32,2 1,26 and 37 appear printed, the correct values should be 30, 20, 25 and 35. We apologize for these errors.