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The below concerning some of the MADS attributes was forwarded to me from
another list. I am sending this response to the MODS list and a copy to
the original list, but I'm not sure if it'll be posted since I'm not
subscribed (someone please forward if it isn't posted).

The reason that relatedType was made optional was because of
transformations between MARC authorities and MADS where the relationship
type isn't specified. However, looking back at it, we did add
"otherRelated", so there is no reason why it can't be required and
"otherRelated" used where the relationship is unspecified.

As for authority, we made it optional for because there could be a record
for an entity that is not controlled by a specified authority list.
However, we could use something like "local" as a value for that. As for
having a defined list of values, we maintain lists of thesauri and
authority files which have hundreds of entries. Also, we add new values to
these regularly, so wouldn't want to have to maintain a specified list in
the schema. Couldn't we just use a URI to reference these lists of values?

Rebecca
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
^^  Rebecca S. Guenther                                   ^^
^^  Senior Networking and Standards Specialist            ^^
^^  Network Development and MARC Standards Office         ^^
^^  1st and Independence Ave. SE                          ^^
^^  Library of Congress                                   ^^
^^  Washington, DC 20540-4402                             ^^
^^  (202) 707-5092 (voice)    (202) 707-0115 (FAX)        ^^
^^  [log in to unmask]                                          ^^
^^                                                        ^^
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^


> ---------- Forwarded message ----------
> Date: Sat, 05 Jun 2004 12:18:54 +0200
> From: Stefano Mazzocchi <[log in to unmask]>
> To: simile general <[log in to unmask]>
> Subject: Re: Fwd: [MODS] MADS: XML schema for authorities
> Resent-Date: Sat,  5 Jun 2004 06:18:58 -0400 (EDT)
> Resent-From: [log in to unmask]
>
>
> MacKenzie Smith wrote:
>
> >
> > FYI -- this is possibly relevant to the work on name matching since much
> > of the name data comes from MARC name authority records, and this new
> > XML schema is a substitute for that format. It's still XML, but it
> > should make conversion to RDF a lot more straightforward if it's adopted
> > for the big name authority files like the Library of Congresses.
>
> Not sure how "straight forward" this could be.
>
> I've looked at the schema and it's a very general one, it's used to
> encode a bunch of things with the same exact elements and all the
> semantic information is encoded in attribute values.
>
> For example:
>
> <?xml version="1.0" encoding="UTF-8"?>
> <mads xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>        xsi:noNamespaceSchemaLocation="/mads-v.3.xsd">
>       <authority>
>         <topic authority="LCSH">Computer programming</topic>
>       </authority>
>       <refs>
>         <ref relatedType="broader">
>               <topic>Computers</topic>
>         </ref>
>         <ref relatedType="narrower">
>               <topic>Programming languages</topic>
>         </ref>
>         <ref relatedType="otherRelated">
>               <topic>Systems Analysis</topic>
>         </ref>
>       </refs>
> </mads>
>
> <?xml version="1.0" encoding="UTF-8"?>
> <mads xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
>        xsi:noNamespaceSchemaLocation="/mads-v.3.xsd">
>       <authority>
>          <geographic authority="naf">Ceylon</geographic>
>       </authority>
>       <refs>
>          <ref relatedType="later">
>               <geographic>Sri Lanka</geographic>
>          </ref>
>       </refs>
> </mads>
>
> All the semantics is in the attribute values relatedType="" and
> authority="".
>
> relatedType="" values are constrolled by the schema, but the attribute
> itself is optional.
>
> authority="" values are *not* controlled by the schema and the attribute
> is optional.
>
> Converting this schema to a useful RDF is algorithmically impossible
> since too much information is kept implicit and/or optional.
>
> The only graph topology that can be inferred from this MADS schema is
> that some literals have some sort of relationship with others (optinally
> labelled) and that this relationship is optionally backed up by a literal.
>
> If all the attributes were required and all the attributes value were
> controlled and restricted by the schema, then the migration could be
> straightforward.
>
> HTH
>
> > MacKenzie
> >
> >> Date:         Fri, 4 Jun 2004 09:34:04 -0400
> >> Reply-To: Metadata Object Description Schema List <[log in to unmask]>
> >> From: "Rebecca S. Guenther" <[log in to unmask]>
> >> Subject: [MODS] MADS: XML schema for authorities
> >>
> >> In response to numerous requests, the Library of Congress' Network
> >> Development and MARC Standards Office has drafted an XML schema for an
> >> authority element set that may be used to provide metadata about agents
> >> (people, organizations), events, and terms (topics, geographics, genres,
> >> etc.).  This Metadata Authority Description Schema (MADS) was created to
> >> serve as a companion to the Metadata Object Description Schema (MODS).
> >> As such, MADS has a relationship to the MARC 21 Authority format, as MODS
> >> has to MARC 21 Bibliographic-- both carry selected data from MARC 21.
> >> There is a high level of compatibility between the MADS and MODS schemas.
> >> MADS is expressed using the XML schema language of the World Wide Web
> >> Consortium.  Note that once the schema is finalized, a few changes may be
> >> made to MODS for consistency. An example is that MADS uses the term
> >> "event" instead of "conference".
> >>
> >> The MADS draft schema is now available for broad review to inform its
> >> completion. Based on input from prospective users, the schema will be
> >> revised and made available for experimentation. The review period will be
> >> between June 4 and July 16, 2004.
> >>
> >> The Web site is at:
> >> http://www.loc.gov/mads
> >> Included is the XML schema itself, a document describing the purpose of
> >> MADS and details about definitions of the most important elements, and an
> >> outline of elements and attributes. A mapping to the MARC 21 Authority
> >> Format will be available shortly.
> >>
> >> We look forward to comments from prospective users about this new schema.
> >>
> >> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> >> ^^  Rebecca S. Guenther                                   ^^
> >> ^^  Senior Networking and Standards Specialist            ^^
> >> ^^  Network Development and MARC Standards Office         ^^
> >> ^^  1st and Independence Ave. SE                          ^^
> >> ^^  Library of Congress                                   ^^
> >> ^^  Washington, DC 20540-4402                             ^^
> >> ^^  (202) 707-5092 (voice)    (202) 707-0115 (FAX)        ^^
> >> ^^  [log in to unmask]                                          ^^
> >> ^^                                                        ^^
> >> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
> --
> Stefano.
>
>
>