Re: pre-coordination

On Tue, Nov 2, 2010 at 2:46 PM, Ray Denenberg, Library of Congress <
rden@loc.gov> wrote:

> Quote:  'wouldn't the result be loads of syntactically "valid"
> but nonsensical combinations?'
>

The more difficult question is; what meaning, if any,  do pre-combined* LCSH
heading strings have.   If Drabenstott (1998) is correct, then the
interpretation of the order of subdivisions, as applied by catalogers, and
as understood by patrons and reference librarians, does not match the
official interpretation.

Under the official interpretation, a sentential paraphrase is generated by
treating the compound as being right headed, and reading off the modifiers
from  right to left - for example "Weasels -- United States -- Nineteenth
Century -- History" roughly corresponds to  "History of Nineteenth Century
US Weasels".

Even without the problems of user and cataloger understanding, any account
of the semantics of subdivided headings must explain the entailed
relationships between the pre-combined heading and its components.   The
heading used as an example in the previous post bears closer examination.

[Note that subject headings refer to what documents are about - see e.g.
Svenonius (2000, p.130) ]

 (1) Sailboats -- Design and construction -- New Zealand


has the canonical form.

(1a) Sailboats -- New Zealand -- Design and construction


Since the subdivisions are orthogonal, both headings denote the set of
documents *about* "The design and construction of Sailboats in New Zealand".

Since these documents are about the *design and construction* of (Sailboats)
in  (New Zealand), they must necessarily also be about  the the design and
construction of *something, somewhere. *
*
*

(2) Design and construction.


Since everything about (1) must  also about (2), we can infer (from the
definition of *BT* )

(3) Sailboats -- New Zealand -- Design and construction  *BT*  Design and
construction


Since these documents are about (Sailboats) located in *New Zealand * (in
particular, their design and construction), they must necessarily in some
way also be about

(4) New Zealand


Which entails

(5) Sailboats -- New Zealand -- Design and construction  *BT  *New Zealand

Being about the activity design and construction of (Sailboats) in New
Zealand, the documents must be about the activity of  design and
construction of (something) in New Zealand:

(6) New Zealand -- Design and construction


Entailing

(7) Sailboats -- New Zealand -- Design and construction  *BT* New Zealand --
Design and construction


Note also that

(8) New Zealand -- Design and construction *BT *New Zealand

and

(9) New Zealand -- Design and construction *BT *Design and construction

We also have

(10 ) Sailboats -- New Zealand -- Design and construction   *BT *Sailboats
-- Design and construction

(11) Sailboats -- Design and construction *BT *Sailboats
(12) Sailboats -- Design and construction *BT *Design and construction

etc.

These BT relationships form a semi-lattice whose GLB is the most specific
subject.

Note that  the ontological entities  described by documents about
"Sailboats" and "Sailboats -- New Zealand"  are [Sailboats] but documents
about "Sailboats -- New Zealand -- Design and construction"  describe a
[Process].

The geographic subdivision does not change the class of entity, but the
topical subdivision does.

Form/Genre subdivisions confuse matters further, since they refer to the
ontological class of the document itself. Of course, without subdivison
markers ($v or $x), it's impossible to tell from the string form whether a
subdivision that might be a Form/Genre is serving that role, rather than
being a topical modifier.

Simon


Drabenstott, Karen Markey (1998). Understanding subject headings in library
catalogs.

Tech. rep. University of Michigan. url:
http://deepblue.lib.umich.edu/handle/2027.42/57992.


Svenonius, Elaine (2000). The Intellectual Foundation of Information
Organization. Cambridge, Mass.: MIT Press. url:
http://www.netlibrary.com/AccessProduct.aspx?ProductId=39954.