On Fri, Nov 20, 2009 at 7:42 AM, Matthew Phillips <M.E.Phillips_at_dundee.ac.uk
> wrote:
>
> Our lecturer at library school very much emphasised to us that despite the
> (then recent) appearance of NT, BT, RT in the schedules that LCSH was *not*
> a thesaurus, that not all subdivisions could be used anywhere, and that
> there were lots of inconsistencies which made her hesitate to acknowledge it
> had any "design" as such.
>
I have had discussions about this before, and I believe that contra your
lecturer, LCSH is a thesaurus; it's a really, really buggy thesaurus,
disguised as a heading list.
According to Z39.19, "A thesaurus is a controlled vocabulary arranged in a
known order and structured so that the various relationships among terms are
displayed clearly and identified by standardized relationship indicators".
The ended up doing some research on the intended results of the switch to
the BT/NT and RT relationship types.
The conversion was done automatically, using a simple algorithm. If an
old-style entry had a see-also reference to another term, and that term had
a reciprocal reference to the first term, both references were converted to
RT (associative). If the reference was not reciprocated, the reference was
converted to BT (hierarchical). The NT relationship, then as now, is
inferred rather than directly recorded.
This conversion would have worked perfectly, if the original data were
inerrant; unfortunately, this was not the case. Any missing reciprocal
references resulted in an RT being promoted to a BT. The Library did not
have funding to fix these errors at the time of conversion, and noted this
in the announcement of the change, requesting that people *not* notify then
of errors in the syndetic structure, and that references would be fixed as
records were updated. By 2006 less than half of all headings had been
examined.
See my poster from DC 2008: http://www.ibiblio.org/ses/poster.pdf (LCSH is
to Thesaurus as Doorbells are to Mammals).
Mary Dykstra brought up these issues at the time (1988), also raising the
issue of headings that contained multiple concepts. This latter point is
worth making, but is not a required characteristic of thesauri.
Simon
Dykstra, Mary (1988). “LC Subject Headings Disguised as a Thesaurus”. In:
Library Journal 113.4, p42.
Received on Fri Nov 20 2009 - 12:29:06 EST