Simon,

Many thanks for making the case for a broader definition of
"identifiers".

On Tue, 7 Mar 2000, Simon Cox wrote:
> Of course, we have some traditional "identifiers" for people already: names!  
> However, these have some inadequacies, primarily non-uniqueness, so various 
> communities augment names with additional information in order to disambiguate 
> the objects thus identified.  In the cultural and historical community birth 
> and death date is often used, and in the scholarly community, affiliation at 
> time of production is conventional.  Thus "Joe Bloggs, 1834-98" allows us to 
> distinguish a particular Joe Bloggs from all the others, as does "Joe Bloggs, OCLC".  
>
> Note that each of these identifiers includes several components:  
> in the first case, family name, given name, year of birth, year of death; 
> in the second case, family name, given name, affiliation.  So these 
> identifiers might be structured more explicitly still only containing 
> the same information in a form such as 
> 
> family:Bloggs;given:Joe;birthYear:1834;deathYear:1898;
> family:Bloggs;given:Joe;affiliation:OCLC;

This is a classical problem of library science and goes right back to
Sir Panizzi, 1848.  Many of his 91 Rules prescribed which sort of
information to include in an author heading (Location was often the
disambiguator of last resort); when to create cross-references; how to
handle corporate, anonymous, or ambiguous authors; use of honorific
titles, etc.  His rules were, in effect, usage prescriptions for how to
"identify" various types of authors in standard ways (in the sense you
intend).

However, this is not how the Agent WG has addressed the problem.
Rather than proposing standard ways of identifying different sorts of
people, a la Panizzi (and along the lines of the DCAGENT scheme that
Andy has suggested [1]), the Agent qualifier proposal puts forward
potential _elements_ (or "components") of such identifiers as
"qualifiers" of the CCP elements with no guidance on how they should be
combined or formatted in practice.  Panizzi did not simply list all
potential disambiguators -- Location, Pseudonym, Transliterated Name,
Occupation, etc.  He said things like, "For Popes and Cardinals, use X
for this, except when Y."

> family:Bloggs;given:Joe;birthYear:1834;deathYear:1898;
> family:Bloggs;given:Joe;affiliation:OCLC;
>
> Looks like a structured description of Joe Bloggs himself, you are 
> saying to yourself ...  But that breaks the 1:1 rule, doesn't it?  
> Well not really, this time.  I would assert that, when used as a 
> component of an identifier, which is all that the value of any of 
> the CCP elements are allowed to be (see argument above), then these 
> each of the components of these strings are there solely to 
> disambiguate the identity of the guy himself.  They are totally 
> legitimate parts of an identifer.  

However, I would expect any DCMI "recommendation" of such a string to
put its usage into some context and include a warning that those
embedded labels might not dumb down very gracefully.  This is precisely
why I earlier suggested that such recommendations go into a sort of
annotated usage guide.  

In the meantime, the qualifiers we approve are intended, among other
things, as "examples" of good qualifiers.  If "Affiliation", for
example, stands alone without a principle to explain why it is there,
then why not "Email address" or "Eye color" or "Dynasty"?  Different
communities will have good reasons to want to use different labels and
different elements in such strings.

> So, if the agent-core does get up (might be a good idea, but it is a 
> different project), then some pieces of the information that would be 
> stored in that form might also appear as part of a particular form 
> of identifier as well.  In fact, it might be useful for the people 
> designing the two things to collaborate, but they should be quite 
> clear that there are two tasks here:  identification, and description.  

I tend to agree with Andy that these tasks would perhaps be handled
best in a separate Agent Core WG which has a specific remit to consider
agent "identification" (rather than "description") and corresponding
encoding schemes.  Since these schemes would not fit cleanly into
either Core, however, I would prefer to see them in some sort of usage
guide, a la Panizzi, rather than trying to come up with a principle
that labels such multi-element structures as "qualifiers".  In fact,
your email message would be a good start for such a document.

Tom

[1] http://www.mailbase.ac.uk/lists/dc-usage/2000-03/0050.html

_______________________________________________________________________________
Dr. Thomas Baker                                            [log in to unmask]
GMD Library
Schloss Birlinghoven                                           +49-2241-14-2352
53754 Sankt Augustin, Germany                              fax +49-2241-14-2619



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