Re: Provenance usage scenario - releaseTime

Ron--

Could you clarify something about your example?  Initially, you say:

>
snip
> Each article has a metadata
> record that provides information including the embargo date
> for the article. One of the records contains:
> 
> <rdf:RDF  ... namespace decls...>
>  <rdf:Description rdf:about="someArticleURI">
>   <dc:rights rdf:parseType="Resource">
>    <prism:releaseTime>2002-02-14T18:00:00-05:00</prism:releaseTime>
>    <!-- 6:00 PM EST on Valentine's Day -->
>   </dc:rights>
>   <dc:title>Valentine's Day Ideas</dc:title>
>   <dc:publisher>PDQ Publications</dc:publisher>
>  </rdf:Description>
> </rdf:RDF>
> 

Then, in the course of explaining the querying that goes on, you say:

> 
> and then the system queries the provenance database (plus the
> stored metadata records, probably no need to extract all their
> triples into the prov. DB, but that's an implementation detail):
> 
>       <someArticleURI> <D:describedBy> ?M     # M is metadata record URI
>       ?M   <prism:receptionTime>  ?Tgot
>       ?M   <dc:source>  ?FromWho
>       ?M   <x:contains> ?_S                   # _S is statement URI
>       ?_S  <rdf:type>  <rdf:Statement>
>       ?_S  <rdf:subject> <someArticleURI>
>       ?_S  <rdf:predicate> <prism:releaseTime>
>       ?_S  <rdf:object> ?Trel
>
snips the results 
>

Are you assuming that the metadata record M contains the individual
triples that you would expect to see produced from parsing the XML/RDF
you give initially, or does it contain a set of reification quads (the
quads with ?_S as subject) expanded from those triples that would then
be directly matched by the query syntax?  

Comment:  This, I think, illustrates one of the reasons for having a
standard vocabulary for describing statements (you can use it in
queries).  It's still not clear to me how the vocabulary per se helps in
recording  provenance information, since here the provenance is about
the metadata record (which has a URI), not an individual reified
statement.  (On the other hand, this may be close enough:  I can
identify that a given *container* (the metadata record), which does have
a URI, contains a statement that *looks like* a given description, and
the provenance is associated with the container as a whole.)

--Frank

-- 
Frank Manola                   The MITRE Corporation
202 Burlington Road, MS A345   Bedford, MA 01730-1420
mailto:fmanola@mitre.org       voice: 781-271-8147   FAX: 781-271-8752

Received on Friday, 15 February 2002 17:28:05 UTC