In message <[log in to unmask]
uk> on Wed, 20 Sep 2000, Shenton Caroline <[log in to unmask]>
writes
>   Here at the Parliamentary Archives we've become the first UK 
>user of
>the functional thesaurus and classification scheme Keyword AAA for 
>records management.  A number of people have asked us for more 
>information so here it is (this note will also appear in the next SoA 
>Newsletter).

I was very interested to see this and am glad to see that the idea of
standardising indexing terminology is becoming yet more widely accepted.

However, I would like to raise a note of caution about "Keyword AAA",
because although it calls itself a "thesaurus" it is not one which
complies with national and international standards for thesaurus
construction such as BS5723:1987; ISO2788-1986 and ANSI/NISO
Z39.19-1993. It uses some of the terminology of these standards, but
with meanings very different from those which they define, so that there
is great potential for confusion.

Keyword AAA would be more properly described as a tool for constructing
pre-coordinated alphabetical subject headings, for use in file titles or
for browsing a sequence of items in an "alphabetico-classed"
arrangement. It prescribes certain terms that should be used first in a
subject heading string, and then says what subheadings you can use under
these, to several levels. In this respect it is more akin to a system
like Library of Congress Subject Headings than to a thesaurus as defined
in the standards. 

The standards cited above are primarily concerned with inherent
relationships between concepts. They would allow relationships such as 

    agenda papers
        broader term: documents

    documents
        narrower term: agenda papers

because "agenda papers" are inherently documents in any context. They
are a "kind of" document, so the specific-generic relationship is valid.

Keyword AAA, however, shows the relationship

    Agenda papers
        Broader Term
            MEETINGS

which is to be interpreted to mean that "agenda papers" may be used as a
subheading under "meetings" when constructing an indexing string such as 
"MEETINGS - agenda papers" 

Anyone familiar with standard thesaurus terminology would take this to
imply that "agenda papers" are a "kind of" meeting, which is clearly not
the case. This is very confusing for people who are familiar with, or in
the process of learning about, standard thesauri.

Such differences of meaning and structure will cause problems to anyone
who tries to combine a thesaurus which does follow the standards, such
as the UNESCO thesaurus, with Keyword AAA. They might wish to do this in
order to supplement it by providing a wider range of subject indexing
terms.

Keyword AAA emphasises its coverage of functional terms, but that is a
separate question from its structure. It would be perfectly possible to
create a standard thesaurus with good coverage of functional terms. 

Such a thesaurus could be used to create pre-coordinated indexing
strings by grouping terms together in facets according to the nature of
the concepts they represent and then specifying a citation order of
facets in building index strings. "Function" could be specified as the
leading facet if desired. This is essentially what Keyword AAA does,
though it uses only three facets: "Keyword", "Activity" and "Subject".
These labels do not show the nature of the facet clearly, especially the
first.

The trouble with pre-coordinate systems for the retrieval of specific
topics is that a searcher has to construct a string with the components
in the specified order in order to match that constructed by the
indexer. If the heading "MEETINGS - agenda papers" is used, someone
searching for "Agenda papers" would not find it unless the system
provided some form of permuted or free text searching, which means that
the sequence of terms in the string is irrelevant. Post-coordinate
indexing, as more widely used in computer systems, would assign the two
terms "meetings" and "agenda papers" separately to the document, and a
searcher would find it whether looking for one or both terms. In the
latter case the search statement would be ("meetings" AND "agenda
papers").

Keyword AAA contains a useful list of indexing terms, but people using
it should not expect its structure to be handled properly by software
designed for use with standard thesauri. My warning is just that people
should check thoroughly that it is what they need rather than assuming
that because it is called a thesaurus and has been widely adopted
elsewhere it is necessarily appropriate for their purposes.

For details of the principles of thesaurus construction according to
standards, with some discussion of faceted classification, I recommend
the authoritative text:

    Thesaurus construction and use : a practical manual / Jean
    Aitchison, Alan Gilchirst and David Bawden. - London  : Aslib, 1997.
    - 212p.

I should say that I have based my comments on an "Evaluation package"
for Keyword AAA sent to me in February 1996. I understand that another
edition has been published since then but that the basic structure is
unchanged.

Leonard Will
-- 
Willpower Information       (Partners: Dr Leonard D Will, Sheena E Will)
Information Management Consultants              Tel: +44 (0)20 8372 0092
27 Calshot Way, Enfield, Middlesex EN2 7BQ, UK. Fax: +44 (0)20 8372 0094
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