W3C home > Mailing lists > Public > www-zig@w3.org > November 2001

holdings-schema proposal

From: Ray Denenberg <rden@loc.gov>
Date: Wed, 14 Nov 2001 10:23:00 -0500
Message-ID: <3BF28C54.B97F1DB4@rs8.loc.gov>
To: ZIG <www-zig@w3.org>
There was a proposal presented at the October ZIG meeting to
change the holdings schema. See:
http://lcweb.loc.gov/z3950/agency/zig/meetings/uk2001/holdings.html

There was objection to the proposal, and we ended the
meeting with no clear path towards resolution. There was
agreement at the meeting to discuss this over the list, but
there has been little discussion and no progress towards
resolution (as far as I can tell).  I've recently been asked
(privately) to see if we can move the discussion along
towards consensus.

I would like to begin by trying to describe the problem in
my own words, partly to get a better understanding myself.

BibPart may have "child" bibParts, and this is represented
by recursion, that is, Bibpart  includes an element
childBibPart whose data type is BibPart.  Bibpart in
addition includes elements enumeration and chronology; these
two elements would occur within the child bibparts, as well
as the top level bib part.

Enumeration and chronology occur with each bibPart, and they
too are viewed as hierarchical, for example in the
enumeration  "volume 5, Issue 2",  "Issue 2" is subordinate
to "volume 5".  It is claimed that the schema cannot express
"volume 5, issue 2" as a flat value. (Why it can't isn't
clear to me. There doesn't seem to be any restriction on the
value, but let's assume you can't do it, for argument
sake.)  So the suggestion is that enumeration and
chronology  each be defined as individually recursive, to
allow children, thus to express the subordinate relation.
Thus every bibPart (top level and children) would have a
recursively defined enumeration and a recursively defined
chronology.

Those who oppose the proposal suggest that the recursive
definition of bibPart is sufficient recursion to recurse
these two elements (implicit recursion). In other word,
suppose there aren't really any child bib parts, but there
are "child" chronologies for the single bib part. You could
artificially recurse bibpart to effect the recursion.


That's my summary of the proposal and the two positions.  Is
this a reasonable interpretation?


If so, I have two observations/opinions:

1. I don't think that artificial recursion of bibPart (i.e.
implicit recursion) is a good thing. You shouldn't recurse
bibpart unless there is a child bibpart. If you do, you have
a semantic mess. Suppose we adopt these semantic and there
is a child bibpart:  how would you know whether the
recurring enumeration/chronology applies to the child or the
parent?

2. On the other hand, it seems like overkill to recurse
enumeration and/or chronology. Why can't they simply be made
repeatable? I.e. allow multiple occurences, where the
semantics of multiple occurences is that the N+1th occurence
is subordinate to the Nth.

Comments please!


--Ray



--
Ray Denenberg
Library of Congress
rden@loc.gov
202-707-5795
Received on Wednesday, 14 November 2001 10:22:59 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Thursday, 29 October 2009 06:12:22 GMT