[Sigia-l] precoordinate indexing

[AF Cossham]

> From: Peter Van Dijck <peter at poorbuthappy.com>
> Date: Wed, 01 Dec 2004 17:03:29 +0100

> Question: I'm trying to figure out what "precoordinate indexing" really
> means, in a web context.

> Let's say we have an article about Shakespeare's lovelife. In
> precoordinate indexing, we have to put that under the categories:
> - Shakespeare
> - Skakespeare's lovelife
> - lovelife
> whereas in postcoordinate indexing, we have to put it under the categories
> - Shakespeare
> - lovelife
> and the system will also show it under Shakespeare's lovelife.

The system will NOT also show it under Shakespeare's lovelife, or lovelife
Shakespeare for that matter, unless you have decided that it should. (or let
me rephrase that, most database software that I am familiar with - primarily
library oriented- does not).
You wouldn't want it to unless you were sticking to pretty straightforward
concepts. Something about, for example, financing the care of the elderly in
rest homes and hospitals in Australia could have
- elderly
- rest homes
- hospitals
- Australia
- finance
and combining all of those in all the possible combinations of all terms
would not necessarily be useful or meaningful to someone trying to find
this.

This doesn't mean that you wouldn't want to use all the terms, or even a
selection of them. And it is quite possible that you might have two sets or
groups of terms, both of which are applicable to the one item, in the same
way that in a library catalogue you can have two different pre-coordinate
subject headings which don't include any of the same terms (or at best, just
the geographical one).


> Something like that. In precoordinate, you have to list out all the
> combinations, in post-coordinate, you let the system/user generate
> combinations. Is that correct?
Yes, that's quite correct.

> And if so, is it correct to say that
> these concepts are useful in a manual environment, but when you're
> dealing with databases and such, the concept of precoordinate indexing
> becomes pretty much irrelevant?

No, don't agree. Pre-coordinate indexing looked at from one angle simply
expresses the structure of that particular part of the classification /
thesaurus / subject headings in use. So, you still want to be able to search
on aspects or elements of the pre-coordinate term, but ALSO to use the whole
term to establish the context of the item WITHIN the database itself and in
relation to other items.

> This page 
> http://www.archivists.org/glossary/term_details.asp?DefinitionKey=989
> says: "The flexibility associated with postcoordinate systems is lost
> when index terms must be printed out on paper or on conventional catalog
> cards."
Yep - post-coordinate does not work well in a paper based environment. But
why would you print or use catalogue cards when even a basic database or
spreadsheet in excel can do it so much better for a small collection, and
you would NEVER use paper/card for a large collection.

Regards,
Amanda Cossham