On Tue, 28 May 2002, Thomas Baker wrote:
> Dear all,
>
> I would like to consider the relationship between the
> "canonical" documentation of DCMI metadata terms maintained by
> the Usage Board and the various schema representations of the
> same.
I agree it is essential we have one canonical source for documenting DCMI
semantics, and I think that source needs to be the Vocabulary Management
System... whether the VMS is your text files manipulated by Perl scripts
or a more richly functional database application.
That approach is reflected in the Roadmap we produced for
the VMS and Registry following the Tokyo AB meeting, see
DCMI Roadmap for development of Vocabulary Management and Schema Registry
Systems
http://dublincore.org/groups/registry/DCMI-reg-roadmapv4.html
As you suggest we now need to consider whether a 'text representation' is
a sustainable form for a 'Vocabulary Mangement System'. I suggested a list
of 'requirement' for a VMS in the RoadMap (for comment by the Usage
Board). I think it worthwhile to re-visit these requirements and consider
wheter they are valid and if they would be fulfilled by text files rather
than a ' database' VMS.
fwiw my opinion would be that text based is a good start, but that some
more complex functionality that may need to be introduced in future ( e.g.
keeping track of multilingual representations, keeping track of 'proposed'
terms) may, in time, need a database.
Also all the 'reports' (schemas) output from the 'canonical text files'
would need automating and maybe that would be easier from a database
rather than from text files ???
see the section of the RoadMap document that says the VMS will need
<quote>
4.1 To provide authoritative outputs of DCMI vocabulary in various formats
as required (e.g. RDF schemas, XML schemas, text versions of descriptions
of terms, etc).
</quote>
As regards how much of the information contained within the VMS (currently
the text files) needs to be contained within a RDF schema, then I think we
need to consider how easily the VMS can spit out schemas... different
applications will want simpler or rcher schemas I suppose?
If the 'content' of RDF schemas need to be pre-defined (which I think it
does in this phase of the VMS) then we do have
requirements for the DCMI Registry, see section 5 of the RoadMap. Note
the requirements include 'structure' of the DCMI vocabulary e.g.
associating schemes with a particular element, but not historical
information about 'decisions'. As proposed the DCMI Registry provides
information about the current version of terms, not an historical audit
trail, so does not need information on the decision history. Note tho the
Registry may need to have info on status of a term so this may need to go
into the RDF schema..
I imagine the web pages acting as a 'user reference for DCMI terms' on the
DCMI web site would have similar requirements to the Registry? I imagine
such user guidance would want to give current info not an historical
trail?? So references to 'decisions' of the Usage Board would not be
needed there either? So I think once we have decided a sub-set of the VMS
data that needs to go to the Web based user guidance docs that sub-set
will also fit for the Registry??
Rachel
For info extract of the RoadMap doc giving requirements of the Registry:
5. VMT-Registry API
Important: this section awaits comment by Usage Board
5.1 To provide output of authoritative description of all current DCMI
terms in format suitable for import to Registry (currently this would be
by means of schemas in RDFS).
5.2 To ensure RDFS schemas expressing the DCMI vocabulary indicate the
structure and relationship between terms (reflecting the DC 'grammar' of
elements, element refinements, controlled vocabularies and schemes). The
schemas will also need to include all information required by people
seeking information about terms i.e. Name, Label, Registration Authority,
Language, Definition, Comment.
(**** Note: depending on the significance of the possible values of
'Status' attribute this attribute may well need to be added to this
list...)
5.3 To provide regular updates of the schemas
Rachel
---------------------------------------------------------------------------
Rachel Heery
UKOLN
University of Bath tel: +44 (0)1225 826724
Bath, BA2 7AY, UK fax: +44 (0)1225 826838
http://www.ukoln.ac.uk/
|
