PERSPECTIVE PAPER:

LIBRARY SCIENCE

Derek Austin
The British Library
Introduction

On the understanding that a respect for terminology is necessary in a paper likely to beread by linguists, I should perhaps start by reviewing the connotations of the term library,
before identifying one particular type as the standpoint from which I shall consider the
keynote document by Sparck Jones and Kay (1973). Libraries are, of course, as diverse as
the people or organisations which created them, and can be categorised in a number ofways, only some of which are relevant in the present context. I believe that threeparticular factors have a bearing or the design or choice of an indexing system:
1. The size of the collection.
2. Types of media collected.
3. The subject fields covered.
On the basis of size alone, we can immediately exclude a number of small (and especiallyprivate or semi-private) collections from these deliberations on the grounds that thesehave no need for the sophisticated techniques of modern information retrieval. Even
within our own homes, most of us can usually locate a relevant book or paper from acollection which may run to several hundreds of items, simply by using our memories.
But the need for something less vulnerable than personal recollection tends to increase
with the size of the collection. The small firm or institutional library could perhaps
manage reasonably well with a simple manually-operated keyword system, though thiswould become inadequate at the level of, say, a public or small university library, while aneven more complex system is needed for a really large collection, such as a state or
national library, or the library of one of the older established universities, especially when
their collections are acquired through legal deposit as well as by exchange and purchase.
When we consider libraries in terms of the media they hold, we are clearly in an age ofincreasing diversification.
Librarians will, without doubt, be dealing with printed
materials for a considerable time to come; probably for as long as any of us can foresee.
But we should remember that printed materials is not a synonym for the printed word;
many of these items, such as maps, prints and photographs, possess undoubted subject
content, but are not amenable to verbal analysis without the intervention of a humanindexer or abstractor. Increasingly, libraries are also collecting materials produced by what
are still called non-conventional means, including audio-visual materials (such as films,
tape-slide sets, models and videotipes), as well as microform and machine-readable
versions of the more conventional books and journal papers.

45

DerekAustinThe field of discourse covered by a collection represents one of the more significant, asv e i l as one of the most neglected, factors in selecting an index system. Again, the range isenormous and can vary f r o m a collection devoted to a single and highly specific topic,
such as high speed aerodynamics, to more diverse but still relatively restricted fields, suchas women's rights, engineering or geography, and so on to completely pan-disciplinary
collections, such as those in public, university or national libraries.
Considering the range of these variables, it is clear that no one librarian can speak onbehalf of the whole profession, or even pretend to represent a majority view. Perhaps,
therefore, I should declare my library background, on the understanding that this could
colour the viewpoints which follow.
I am a member of a research team which isconcerned with the subject approach to documents (in the widest sense) in the British
Library. This is a relatively new national library, formed by the amalgamation of anumber of older but separate institutions, su:h as the former British Museum Library, theNational Central Library, and the British National Bibliography. Since the British Library
was born in the age of the computer, all our researches have been machine-oriented since
the library's inception.
Consequently, my special interest is in exploring the subject
approach to machine-held files which represent the holdings of a large, pan-disciplinary
and multi-media collection: possibly one of the largest libraries in the world. Apart f r o ma natural concern with its own collections, the British Library is aiso (like many similar
institutions) responsible f o r creating c o u n t r y - o f - o r i g i n information on recent publications
and contributing these to the international M A R C ( M A c h i n e Readable Catalogue)
network.
It also provides, f o r the library community at large, catalogue and indexing
services f r o m a centralised data base. In addition, we process materials held by otherinstitutions, such as certain classes of archives held in the Public Record Office, and arange of audio-visual materials (which happen to slip through our copyright net) held in
various academic institutions. Taking these various sources of material together, it can beseen that we are, in fact, working towards the concept of a unified national data basecovering all fields and media, and constructed in accordance with a single, though still
evolving, set of standards. If present plans mature, this data base should become publicly
available in an interactive mode, at both the national and international level, w i t h i n thenext few years. It could be argued that this is hardly the viewpoint of a typical librarian( i f such an entity exists); I would stress, however, that this is a real world situation, andone which offers challenges not, I think, considered sufficiently by Sparck Jones and Kay.
Effects of the Collection Type on the Choice of an Information Retrieval System
As noted above, the size of the collection can have a bearing on the type of retrieval
system installed; it was even suggested that there may be no need to impose any system,other than the memory of us owner or curator, upon the small collection. A t the opposite
end of the scale, a really large collection, such as the Library of Congress or the British
Library, must introduce some means for subject access to its materials i f these are to be
f u l l y utilised, not simply conserved. Hopefully, we are now leaving the era when the way
to the contents of a large library was entirely through the author and title catalogue, which
virtually meant that the scholar had to conduct his own subject enquiries, as best he could,
before he entered the library.
In terms of subject retrieval, especially in a mechanised e n - vironment, the provision ofaccess to a large collection entails the creation of a large data base. The new British
Library data base, now at the advanced planning stage, has been designed f r o m the outset
to deal with what is called a mtga-document
collection.
A t first sight, it may seem that
this matter of size is scarcely relevant to the choice of an indexing system, but a moment's
reflection will show that this is not true. Many of the projects reviewec with apparent
favour by Sparck Jones and Kay. particularly those concerned with identifying relevant
items by applying the techniques of term association and statistical clumping, call for theprovision of some free text (preferably an abstract) for each o f the documents in thecollection. At present, the provision of text on the scale needed to apply these techniques

46Perspective Paper:

Library Scienceto the holdings of a national or university library would be completely impracticable.
Many of these institutions measure their intakes in miles or kilometers per annum, notnumbers of items. Even assuming that we could afford to house and pay the army ofabstractors needed to deal with intakes on this scale (large numbers of which arrive
without abstracts of any kind), we should still be faced by the costs of keyboarding andproofreading all these data, and would then have to face the enormous problems of filecapacity. Again, it might be argued that these large collections do not represent typicalcases, but unfortunately these are the libraries which are most in need of help fromadvanced technology, and they are also the institutions best endowed, in terms of financeand equipment, to apply the new techniques. This rather suggests that we need to lower
our sights somewhat, and consider the use of professional indexers, rather than abstractors,
to prepare summary subject statements when dealing with intakes at this level.
This viewpoint is reinforced when we consider the types of media held in thesecollections. Abstracts, or even descriptive titles (when they occur) may form part of thedata provided by publishers of some classes of printed materials, but this hardly applies tophotographs or maps, tape-slide sets or videotapes, none of which fits into the category of
printed matter as this term is usually understood. Certainly, none of these materials is
amenable to free text searching, yet they still constitute part of the holdings of many
libraries, and have enormous value from the subject point of view.
When considering the choice of a subject system, the factors reviewed above (i.e. the sizeof the collection and the types of media) are relatively insignificant compared with thethird and final factor, i.e. the subject fields held within a given institution. It is notenough to draw a distinction between a specialised collection on the one hand, and thegeneral or pan-disciplinary library on the other. Even within the category of specialised
collections, we need to distinguish subject fields further in terms of their relative hardness
and softness, on the understanding that these factors can also affect the ability of a
retrieval system to locate relevant items quickly and accurately.
Unfortunately, nosatisfactory measures have been established for determining relative hardness or softness.
Storer (1967), writing as a sociologist, has suggested certain criteria which relate to theharder sciences, such as impersonal relationships between members, an extensive use ofmathematics, an easy detection of error or irrelevance in written communications, andinvariant concepts. I would suggest that the softer sciences might be characterised by thefollowing:
1. The terms used to describe an entity or phenomenon tend to vary with theframes of reference of the observer.
2. Terms used in communications tend to lack invariant meanings.
3. The relationships between concepts are not self-evident: that is to say, we cannot
readily deduce the connotation of a given term until we know its context, and inparticular its syntactical relationships with the other terms assigned to a
document.
Considered in terms of these criteria, we might infer that engineering belongs to theharder sciences, on the grounds that terms in this field necessarily tend to acquire
relatively fixed and widely-known meanings, while their roles vis-a-vis other terms
assigned to a document (whether in an abstract, or in a subject index) are usually
self-evident. For example, we could reasonably assume that an engineer faced by a set of
unrelated keywords such as Hydraulic system. Drakes, Failure and Leakage would be able
to deduce without aids that the term Brakes represents a patient to the concept Failure,
and that Leakage applies to the Hydraulic system, and in this case is probably acontributory factor in the failure of the brakes. Hov/ever, we face a rather different
situation when we consider terms at the softer end of the subject spectrum, in particular47

Derek Austin
the social sciences. In the first place, terms in these fields do not possess clearcut
meanings. Foskett (1974) has pointed out that "The same thing can be identified by manydifferent terms, and the same term may mean many different things". It has been said
that the meanings ascribed by sociologists to terms such as Group and Society will vary not
only according to which side of the Atlantic the author resides, but even the particular
university he attended. These fields are also characterised by a general variability in theirsyntactical relationships, in the sense that we cannot readily deduce, from a set of
unrelated keywords, who was doing what to whom. This is because it is frequently
possible to reverse the roles of object and subject in sociological writing, and still makevalid sense. For example, a set of keywords such as Women, Managers, Attitudes andEmployees is liable to a number of interpretations, e.g. Manager's attitudes to theirwomen employees, or The attitudes of employees to women managers, and so on, each ofwhich is a different but quite valid subject in its own right.
I would suggest that these are important matters in the present context, mainly on the
grounds that many of the systems reviewed by Spark Jones and Kay depend for theireffectiveness on the dttection of term cooccurrence, and take little if any account of theways in which the terms were interrelated. That is. terms are recognised as members of a
set associated, either manually or automatically, with a given document, leaving the user toinfer for himself exactly how they were syntactically related. Even in the harder sciences,it seems that this technique of post-coordination can lead to confusion, for the simple
reason that index users necessarily perceive these terms sequentially, however they were
derived or stored in the first place. In this connection, Bohnert(3) has observed that
The standard requirement of two or more terms to be used in coordinate index
systems creates opportunities for the terms, when arranged sequentially, to lookdangerously like words in a sentence - like a message of some kind.
Thisoccurs because we are taught to recognise a great variety of sentential structures
while learning to read. Therefore, whenever we come across a sequence ofwords resembling a sentence, we begin to believe that it may be one.
It only remains to state the obvious: if a lack of some means for indicating syntactical
relations can lead to noise in a retrieval system covering a specific subject field, it seems
reasonable to assume that this situation will be even more serious in a large collection
covering the entire subject spectrum. In that case a user who is interested in, say,management, and conducts a search in a post-coordinate mode for documents containing
keywords such as Hospitals and Administration is likely to be faced by works on The
administration of drugs to elderly patients in hospitals. Sparck Jones and Kay consider
some of the mechanisms intended to eliminate false drops of this kind in post-coordinate
systems, but some of these, such as coded roles appended to indexing terms, are of
doubtful efficiency; a term such as Administration possesses exactly the same syntacticalrole in each of the different subjects used as examples above. To assist the user further incases such as this, we might stipulate two extra requirements in an indexing system:
1. When the system responds to the user, it should be capable of displaying not
only the terms which were present in the enquiry, but also any other terms
which were assigned to a document.
2. Since the order in which terms are displayed to the user can affect theirinterpretation, this iinguistic feature should be exploited deliberately. That is,
index terms should be organised into a sequence which is likely to suggest theircorrect interpretation.

48

Perspective Paper:

Library

ScienceIn other words, we need to design a system which responds to the input of certain cue
words by displaying (e.g.,
on a V D U ) a variety of syntactically organised outputs
containing those cue words, together with any associated terms assigned to a document orgroup of documents. The user could then scan these outputs, rejecting some, and selecting
others which he judges to be relevant, before any attempt is made to display the citations.
Although it was stipulated that this output should be organised in a meaningful way, it is
not suggested that a grammar of any kind should be imposed upon the user, who could
still approach the data base in a post-coordinate mode, using keywords in any order as his
input, plus perhaps some f o r m of weighting and the usual Boolean functions.
The
syntactical information needed to organise the output would remain the province of theindexers who create the data base, and should stay w i t h i n the system.
It is realised that the stipulation of these f a i r l y sophisticated requirements, particularly
insofar as they concern the f o r m in which index i n f o r m a t i o n is displayed, runs contrary to
the findings of various tests on indexing systems, most of which appear to indicate thatthe level of sophistication, the f o r m of the output, and even the source of the index terms
themselves, have little effect on the performance of a system. Many of these tests (e.g.,
Cleverdon et al, and Salton) are considered by Sparck Jones and Kay, who see them as
evidence supporting the hypothesis "...that simple indexing methods can compete withcomplex ones" (p. 126). However, some points about these tests should also be noted:
1. They were carried out under artificial laboratory conditions far removed f r o m
the hurly burly of a working reference library.
2. They were conducted on comparatively small samples compared with the average public library.

very small

indeed

3. These samples were restricted to documents covering a single subject field.
4. The fields selected (e.g., precision engineering, and high speed aerodynamics)
were generally at the harder end of the subject spectrum, which is where the useof an imposed syntax is least likely to be necessary.
5. None of the tests was concerned with printed indexes.
These inadequacies have, in fact, been recognised f o r some time, but steps towards theircorrection are relatively recent. This seems an appropriate point to mention a recent workby Sparck Jones and van Rijsbergen (1975) in which they set out to examine thecharacteristics of the ideal test collection. A passing mention should also be made o f atest of printed indexes now in progress at the College of Librarianship Wales, though thiswork, insofar as it can be judged by the intermediate report (Keen et al., 1975), seems tocall for an element of caution. Ostensibly the test sets out to compare the relative
performance of various printed outputs, e.g., K W I C , K W O C , Articulated, PRECIS andothers. In fact, however, all these outputs were generated f r o m a set of PRECIS strings
prepared by a member of the staff of the British Library, and these were then manipulated
in various ways to simulate the outputs of all the alternative systems. Not surprisingly, theperformance of all the systems tested was remarkably similar.
It is hoped that thismethodology will be revised in the later stages of the project: that is to say, the K W I C
index will be constructed by an indexer skilled in this particular technique, without directcontact or reference to the work of the other inders.

49DerekAustin

Display of Indexing Data
Throughout their book, Sparck Jones and Kay seem to advocate further researches into theuse of computers to extract sets of keywords f r o m machine-readable texts, and theyfurther consider that, in due time, the machine w i l l match the performance o f the humanindexer in locating relevant documents on the basis of term cooccurrence. I can think o f
no reasons f o r dcubting this assumption provided that the computer acts as a black box
intermediary between the readers and the actual documents, its principal function being torelate a set of keywords or index terms to the texts in which they occurred. The user
approaching the system, and offering an enquiry in a simila" f o r m (i.e. as a set of
unrelated keywords) would presumably then be presented directly with citations, such as
brief catalogue entries, f r o m which (given expressive titles, which cannot be taken for
granted) he would then select the possibly relevant, rejecting all others. Given this as thegoal, it would be reasonable to agree with the authors t h a t
1. "Relatively simple indexing techniques can be as effective as more complex ones,
and automatic methods of providing simple index descriptions are as effective as
manual ones" (Sparck Jones and Kay, 1973, p. 126).
2. "For the special purposes of document retrieval general linguistic theories are
not recuired" (p. 198).
For the reasons set out earlier, I cannot quite see the computer in this black box role
offering any immediate help to t i e hard pressed reference librarian, especially one
concerned with a large and pan-disciplinary collection. Perhaps it is simply a matter ofconservatism, but I still hold out some hope for traditional index entries, displayed in ameaningful way, and functioning as a primary select-or-reject screen between the
documents and their users. Seen f r o m this viewpoint, I feel that the authors focussed
attention too closely upon post-coordinate systems (whether manual or mechanised),
without taking sufficient account of the recent developments in the field o f printed andpre-coordmated indexes, especially those which involve considerable use of the computerin their production.
Before reviewing some of these developments, we should perhaps pause and consider thecurrent use of the term printed indexes, just in case this still conjures up a mental pictureof the scholar labouring over a file of cards or slips of paper which are then sent o f f , withsuitable typographic instructions to a compositor. Traditionally, this is exactly what wasmeant by a printed index, which might, as in a typical back-of-the-book index, refer theuser to a position in a separate sequence, in which case it would be known as a two-stage
index; alternatively, each entry might be followed immediately by one or more citations tomake a one-stage index, as in a card catalogue or bibliogr; phy organised under subject
headings. The function in each case is the same: to present to the u;;;r one or more words
which together express, in a succinct f o r m and with minimal ambiguity, the subject of adocument. It was felt at one time that this message-carrying function of the subject index
might change with the introduction of computers, which lend themselves readily to freetext searching. Experience has shown, however, that this is noi the case. It has evenbecome clear that the properties associated with the traditional forms of printed index are
equally necessary in other forms of human-readable output, such as computer-output
microform (COM) either on f i l m or fiche, or in the display of index terms as meaningful
sequences on VDU's or at teletype terminals. For this reascn, Professor Vickery of the
University of London library school has suggested the term visible indexes as a more
appropriate name. In the present paper, however, the older term printed indexes w i l l be
used to denote these various forms of output.

50

Perspective Paper:

Library Science

The past ten years or so have seen some significant changes in printed index production,
mostly resulting from the introduction of the third generation of computers into thelibrary world. Up to that time, most subject indexes in catalogues or bibliographies had
been modelled on one of two types:(a) Subject headings, such as those used in the Library of Congress (LCSH), or the U.S.
National Library of medicine (MeSH). When using these systems, one or more headings,
which may consist of compound phrases but function essentially as keywords, are selectedfrom a prescribed list and assigned to the document in hand. For example, the following
three headings might be assigned to a work on The administration of drugs to elderly
patients in hospitals:
1 Hospitals
2 Aged3 Drugs. Administration
None of these headings attempts to be co-extensive with the subject of the document
They can be used in a two-stage mode (similar to the keyword subject index in the bookby Sparck Jones and Kay), or as a one-stage index, in which case all the citations to whicha given heading had been assigned would be printed immediately after the heading, as in
the National Union Catalog. This can involve the user in a fairly tedious search,especially if he enters the catalogue at an overworked term such as Hospitals. When usinga system of subject headings, no attempt is made to correlate the terms which function asheadings and the classification scheme (if any) which is used to organise the shelves. Eachof these means for organising subject data are seen as completely different in terms ofboth function and structure.
(b) Chain indexing (and its derivatives) is based more obviously on classificatory
principles. Unlike a subject heading system, a chain index is necessarily two-stage: that is,
the user is re-directed by means of an address (such as a class number) to a position in asecond field where the appropriate citations are displayed. As generally used, a document
is classified before it is indexed, and the order of terms in a set of chain index entries
then reflects, and is therefore determined by, the order in which concepts were introduced
into the systematic schedules. If the subject considered above had been assigned, forexample, to the class 615.58 in the Dewey Decimal Classification, the following chainindex entries would be produced:
1 Medicine

610

2 Pharmacology: Medicine

615

3 Therapeutics: Pharmacology

615.5

4 Drug therapy

615.58This is as far as these schedules allow us to go in expressing this particular subject.
Coates (1968) has broken free from the constraints imposed by a classification scheme,
and has successfully computerised the production of a chain index by applying thistechnique to strings of terms organised according to a general citation formula: something
approaching an indexing grammar.

51

Derek Austin
Apart f r o m the chain index produced by Coates, neither of the methods considered above
is based on obvious linguistic principles, and it is not surprising that they were generally
overlooked b) Sparck Jones and Kay. The main advantages of these systems lie in the easeand economy with which they can be applied, but this has to be balanced against certain
disadvantages seen f r o m the user's point of view:

1. Their lack of co-extensiveness.
2. A frequent loss of useful entry points (e.g. the loss of the termin the examples above).

Administration

3. A n occasional latent ambiguity, especially in a chain index to a classified f i l e ,where the order of concepts tends to reflect their relative importance as
indicators of shelf position, without necessarily taking account o f the meaningof the resulting entries.
A serious attempt to overcome these problems, using the computer to generate a f u l l set ofco-extensive index entries out of a single input string, was made by Aimitage and Lynch(1967) at Sheffield University. This Articulated Subject Index (ASI) is based on what
Sparck Jones and Kay call quasi-linguistic
principles (p. 61). Presumably the choice ofthe epithet quasi expresses the fact that the computer does not attempt a full-scalesemantic analysis, but is programmed to recognise prepositions as articulation points whengenerating entries. Insofar as prepositions frequently indicate deep cases, I should havethought that this would count as a genuine attempt to apply linguistic principles. I f ASI
procedures were applied to the subject considered earlier, the computer would generate thef o l l o w i n g entries:
administrationof drugs to elderly patients in hospitals
drugs
administration of, to elderly patients in hospitals
patients
elderly, in hospitals, administration of drugs toelderly patientsin hospitals, administration of drugs to
hospitals
elderly patients i n . administration of drugs to
It is worth noting, in passing, that the techniques used in the ASI were derived f r o m astudy of human-produced index entries in Chemical Abstracts.
Examples of this index
can be seen in World Textile
Abstracts.

PRECISIn the text by Sparck Jones and Kay it is stated that "...Indexing languages are generallyparasitic on natural language, that is, are derived f r o m or dependent on it, but they areintended to be in some sense more logical" (1973, p46).
I would regard this as areasonable description of PRECIS (Austin, 1974c), the latest member of the f a m i l y ofvisible indexes now being considered.
Unfortunately, the published accounts of thissystem did not begin to appear until after the work by Spark Jones and Kay had gone to52Perspective Paper:

Library Science

press. Certainly, PRECIS is parasitic on natural language, insofar as: (1) the order ofterms in input strings, and in the entries generated by a range of transformaiionalalgorithms out of these strings, is based by intent upon a subset of the declarative word
strirgs occurring in natural language; (2) the system also employs a number of NL devices,such as machine-produced prepositional phrases, to resolve latent ambiguities in entries.
At the same time, it also sets out to be more logical than NL, for the sake of achieving not
only collocation in the printed index, but also inter-indexer consistency. For example, onepreferred order of terms in input strings (the passive construction) has been selected fromamong the permutations allowed in natural language, but we have found that this ordercan be taught more readily through reference to logical principles such as context
dependency and time of conceptualisation.
The vocabulary of PRECIS is entirely
open-ended, meaning that new terms can be admitted into the system at any time, but it isnevertheless controlled, and terms are assigned to categories in a machine-held thesaurus
constructed in accordance with general principles laid down in an International Standard(IS 2788; see International Standards Organisation, 1975).
This paper is not an appropriate outlet for an account of the techniques of PRECIS; abrief description of the system appears in International Classification (Austin, 1974b). It
is sufficient to note here that the development of PRECIS can be traced back to an
attempt by the staff of the British National Bibliography to automate the production ofan alphabetical subject index to a classified bibliography, the first intention being tocomputerise a chain index similar to that shown above. This attempt proved to beabortive, mainly because it was found through trial and error that consistent, meaningful
and unambiguous entries could not be prodiced algorithmically from strings of terms
organised according to the ways in which concepts are set down in the schedules of alibrary classification. Once this had been established, a special research project was set up
in 1969 to explore a new approach to computer-assisted indexing. This project worked
within the following guidelines:(a) The computer, not the indexer, should produce all the index entries. The indexer
would prepare a single input string containing terms which are the components of index
entries, plus codes which indicate, for example, the indexer's choice of lead terms, andoperators indicating the role of each term vis-a-vis the other concepts in the string, sincethese roles affect the format of the output. The construction of entries would, however,be left to the computer.
(b) Each of the entries produced in this way should be co-extensive with the subject asperceived by the indexer. This should be seen in contrast to the subject headings
considered above, and also to the chain index, where only the final entry is likely toapproach co-extensiveness.
(c) These entries should be meaningful according to normal frames of reference: that is tosay, the order of terms should suggest, of its own accord, the correct interpretation of an
entry, so that a reader could use the index with a minimum of instruction.
(d) The order of terms in input strings should be regulated by a single and easily taught
logical system which would produce effective entries across the entire subject spectrum,i.e., in physics and also metaphysics, politics and music.
(e) Finally, to support the terms selected as entry points to the alphabetical file, the systemshould be equipped with means for producing See and See Also references between
semantically related terms held at random access addresses in a computerised thesaurus.

53

Derek Austin
It might be claimed in hindsight that PRECIS is based upon logico-linguistic principles,
which certainly sounds highly respectable, but it has to be admitted that the designers of
the system had no such goal in mind at the start of their researches. The system developedin an ad hoc and entirely heuristic fashion. Once a basic set of entry construction
algorithms had been devised and programmed, attention was mainly focussed upon theorder of terms in input strings as the most likely source of occasional y ambiguous or evennonsensical ^entries. The outputs from successive modifications of these strings were thenjudged subjectively, leading if necessary to further modifications to the input or the
programs. It was realised only slowly that this process was taking us away from thetraditional approach of the indexer to a classified catalogue, who tends to organise terms
according to their relative significance as shelving factors. Instead, we were adopting neworganising principles related to roles or cases in natural language. This overt linguistic
approach was clearly established in the research project spanning 1971-1973, and led tosuch a radical re-design of the system that the subject files of BNB which had been
established during that period were wiped clean at the end of 1973, when a fresh start wasmade with new working procedures and programs. The history of tiese developments,
which post-date the text by Sparck Jones and Kay, were reported in the Journal ofDocumentation in 1974 (Austin, 1974a).
The system described in the PRECIS Manual has been adopted by the British Library as
its main line indexing system, and is also used to produce subject indexes to the Australian
National Bibliography and various other catalogues and bibliographies throughout theworld. This system is now regarded as stable, at least as far as indexing in the English
language is concerned. If applied to the sample subject considered earlier, the indexer
would write the following input string:(1) hospitals(p) patients Si elderly(3) drugs 8w to(2) administration*

and assuming that each of these terms had been marked as a lead, the computer would
respond with the following entries:
Hospitals
Elderly patients. Drugs. Administration
Patients. Hospitals
Elderly patients. Drugs. Administration
Elderly patients. Hospitals
Drugs. Administration
Drugs. Elderly patients. Hospitals
Administration
Administration. Drugs to elderly patients. Hospitals
The fact that PRECIS apparently produces acceptable entries in English has not meant an
end to further enquiries. Not surprisingly, the team responsible for developing the system
could not resist the temptation to try out the syntax in a range of non-English languages.
These experiments have been encouraging; the results revealed the need for extra codes andprocedures to deal with certain kinds of surface feature in some groups of languages, suchas inflections and compound terms in the Germanic group, and new routines to handle
these have now been specified. At the deep structure level, however, these tests have54Perspective Paper:

Library Science

shown that the general principles on which the system is based, as expressed in the schemaof role operators (Austin, 1974b,c), are capable of dealing with a wide range of different
languages. In particular, these tests have shown a direct relationship between grammaticalcases and the roles which are used as organising factors in input strings (e.g., location,
object, action, agent, instrument, etc.). This correlation became most apparent whenexperimenting with German and other inflected languages; it could not have been detected
so readily in English, since this language has generally shed the inflections which make thecase of a term explicit.
A project has recently been launched to examine the potential of PRECIS as a translingual
switching system, the goal being the automatic conversion of an input string written in
English, French or German into acceptable entries (as judged by native speakers) in eitherof the other two target languages. As a prelude to these experiments, we have had to
scrutinise the principles which might underlie what Neelameghan (1975) has called anabsolute syntax, that is, a generalised decision-making model for organising terms inindex entries which is independent of any one NL. An attempt is now being made to
examine the extent to which such principles might be invested already in PRECIS, and thisis being reported in a series of articles in Libri. The second of these papers (Sorensen andAustin, 1976) deals with the general syntactical factors involved in the use of PRECIS in a
multilingual context
Conclusion
The linguist might regard these incursions by indexers into his territory as oversimplistic,or even dilettantish. Indeed, the purists among them might even deny that we areconcerned with language at all. As an indexer, I would be willing to cede this point, for
two obvious reasons:(a) Since the language of a printed index is amenable to control at every stage of its
production, it cannot (despite the obvious parasitism noted by Sparck Jones and Kay) be
regarded as a variety of natural language, with all its vagaries. Entries in indexes, andeven the titles of documents, are rarely fully-formed sentences, but consist instead ofsequences of noun phrases, or even single nouns, which express the subjects of documents.
It follows that the indexer has no need to grapple with the complexities of free text which
are the province of the linguist.
(b) The indexer's approach to the design of a system is generally both heuristic andsubjective. He does not slart from some established linguistic basis, and then proceed todesign a system from known premises, bjt rather tends to modify a system until it appears
to function reasonably well, then turns to linguistic theories for supporting evidence andteachable explanations. It is true that modifications may be made to a system as a resultof such contact, but these generally arise through hindsight, and are not the result ofworking a priori from linguistic premises.
Nevertheless, I cannot completely share the views of Sparck Jones and Kay when they
consider that "....the use of syntactic structure in descriptive units and operation on it for
retrieval represented, for example, by the replacement of specific relations by more generalones, seem to owe little to contemporary linguistics" (p. 62). This may be true for thekind of keyword indexing, whether manual or automatic, to which these authors paid
particular attention, but 1 doubt whether it holds for the production of visible indexes,
especially those which employ computers to implement decisions taken by human indexers
and lingiists. Unfortunately, the traffic will almost certainly be one way. Indexers,
especially those who are working in multilingual and pan-disciplinary environments, havemuch to learn from linguists; regretably, I doubt whether indexers have much to offer in
return.

55

Derek Austin
References
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Computer." Journal of Chemical Documentation, 1967, 7, 170-178.
Austin, D. "The Development of PRECIS: a Theoretical and Technical History".
of Documentation, 1974, 30(1), 47-102.

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Austin, D. PRECIS: A Manual of Concept Analysis and Subject Indexing.
BritishNational Bibliography (now Bibliographic Services Division, the British Library), 1974.
Bohnert L. M.
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"Limits of Indexing." In Newman, S.M., ed., Information
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Keen, E. M., et al. EPSILON: Report of the First Stage of an Evaluation of Printed
Subject Indexes bv Laboratory Investigation: Interim Report for the Period October
1V73 to October 1975. College of Librarianship, Wales, 1975. (NOTE: This report isfor restricted circulation only).
Neelameghan, A.
"Absolute Syntax and Structure of an Indexing and Switching
Language." In Proceedings of the Third International
Study Conference onClassification Research, Bombay, January 1975. FID/CR (in press).
Sorensen, J., and Austin, D. "PRECIS in a Multilingual Context, Part 2: A Linguistic and
Logical Explanation of the Syntax." Libri, 1976. [Distributed with the author's paper tothe Workshop participants.]
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Sparc'< Jones, K., and van Rijsbergen, C. J. Report on the Need for and Provision of an'Ideal' Information Retrieval Test Collection.
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