[WEB4LIB] Reality check -- card catalogs don't support graph structure?

[Sheryl Dwinell]

Nick:

I'm not exactly sure if I understand your statement "...every subheading has
just one parent heading?", but I'll take a shot. Library of Congress subject
headings follow certain rules established by LC for subdivision use. There
are some subdivisions that can only be used under particular 'parent
headings'. In other cases, there are 'free-floating' subdivisions that can
be used more freely, but still within some given guidelines. For example,
you can have United States--History, Great Britain--History,
France--History, etc. In online catalogs like ours, where subject headings
can 'rotate', you can search for 'history' and pull up headings that start
with history, as well as headings in which 'history' is a subdivision.

As for 'graph structures', again I'm not quite sure, but I think that the
cross-reference (see & see also references associated with subject headings)
structure of LCSH might fit that description.

You might want to talk to the folks at LC & some catalogers at libraries in
your area (both academic & public) to gain some more insights.  Caution,
mini rant coming: My pet peeve regarding books & articles written by
non-librarians in which libraries are discussed is that about half the time
they contain misleading or incorrect information regarding things like LCSH
and online catalogs and what they can or can't do. It's pretty obvious that
they haven't talked to actual librarians. Ok, end of rant.