[open-bibliography] Proposed definition for /book/book

[John Mark Ockerbloom]

On 07/01/2010 12:24 PM, Tim Spalding wrote:
> For what it's worth, I think people can err in setting up a
> hard-and-fast system. The library world loves binary systems and
> deciding things at the start, not down the road.
>
> For example, a book either does or does not get the LCSH "Man-Woman
> Relations." This is strange, as about 90% of literature involves
> man-woman relationships to some degree or another. (Tagging, which
> allows for degree, is an improvement in this respect.) I would argue
> this sort of relationship has more to do with the physical constraints
> of catalog cards than anything else.

Even outside the constraints of catalog cards, it's often considered
a good idea to leave out "Man-woman relationships" or other subject
descriptors that cover a large portion of a collection, in order to
prevent overload when people go looking for books under that heading.

I didn't take formal cataloger training, but my understand is that
traditionally, you're only supposed to add a subject heading when it's
both a primary and a distinctive characteristic of a work, as opposed
to something that just happens to be featured in it at some level.
The idea is that, when you look up the heading, you should find the books
that are most centrally and definitively about man-women relationships
in your collection, not all the books in your collection that happen
to include men and women relating to each other somewhere in the text.
You can see the usefulness of this kind of policy if you're specifically
trying to do focused research on a previously defined topic.

This is a different use case than you often see in tag-based browsing,
though, where the purpose of subject descriptors isn't so much to
draw your attention to a particular focus, but instead to filter
a large collection into a smaller collection.  (In browsing scenarios
like this, you're not asking "show me the books most concerned with
man-woman relationships", but instead "show me your collection,
filtering out the books that *don't* deal at all
with man-women relationships".)

Of course, in social systems like LibraryThing, you can also draw
attention to particular places in that filter via tag frequencies.  But
that might not quite what a scholarly researcher wants.  "Show me the
books that the most people have associated with man-woman relationships"
tends to filter for popularity more than "show me the books that
are *concerned* most with man-woman relationships".  ("Relationships" might
not be the best example, because this topic is a bit diffuse to begin
with; but the difference is starker when you have a topic that's
featured briefly in many popular works, but deeply in only a few,
more obscure works.)

So there really are two subtly different purposes for subject descriptors
in large catalogs.  Moreover, the "distinctiveness" criterion in the
traditional purpose is *necessarily* dependent on the collection that
it's in; what's distinctive in one collection may be completely commomplace
in another.

One consequence of this is that if you're trying to compose together a large
open collection from a bunch of smaller pre-existing collections, you're
going to have to deal sensibly with the different purposes and contexts
where subject headings have been assigned.  And, hopefully, try to come
up with workable strategies and policies going forward.

John Mark Ockerbloom