Stuart,

Note that the VIAF URI you refer to does NOT identify the U.S. Constitution. The presence/absence of the trailing slash is significant:
 
<http://viaf.org/viaf/179020116> 
	# a FRBR Work
	foaf:name "United States. | Constitution" ;
	#..
	.

<http://viaf.org/viaf/179020116/>
	a foaf:Document ;
	foaf:primaryTopic <http://viaf.org/viaf/179020116> ;
	#...
	.
 
(Note the trailing slash on the latter.)

The former URI (without the trailing slash) identifies the Constitution itself (as a FRBR Work). The latter URI (with the trailing slash) identifies VIAF's *description* of the Constitution. These are two different things that VIAF connects in two ways:

1) by a 303 redirect at the HTTP protocol level from the former to the latter as per: http://www.w3.org/TR/cooluris/#r303gendocument
2) a foaf:primaryTopic relationship inside the data itself.

VIAF also identifies various FRBR Expressions of this Work, but these relationships aren't currently represented in the RDF.

In contrast, the resource located at http://www.archives.gov/exhibits/charters/constitution_transcript.html should map to a FRBR Item.

I realize that BIBFRAME is trying to avoid FRBR, but hopefully it doesn't do so by conflating the identity of these different entities. IMO, the "lightweight abstraction layer needed to express the differences" already exists. It's called owl:ObjectProperty.

Jeff


> -----Original Message-----
> From: Bibliographic Framework Transition Initiative Forum
> [mailto:[log in to unmask]] On Behalf Of stuart yeates
> Sent: Thursday, May 23, 2013 12:18 AM
> To: [log in to unmask]
> Subject: Re: [BIBFRAME] http://bibframe.org/documentation/bibframe-
> authority/ and the "lightweight abstraction layer"
> 
> 
>  > Stuart - can you give the examples you were going to give now VIAF
> is  > back up?
> 
> I believe that, as librarians, we can all see a semantic difference
> between the documents pointed to by these two URIs:
> 
> http://www.archives.gov/exhibits/charters/constitution_transcript.html
> http://viaf.org/viaf/179020116/
> 
> [I'm not interested in the exact semantic differences or the
> terminology we use to express them, that's a kettle of fish to be
> savoured separately].
> 
> I believe that we can agree that future BIBFRAME-based library systems
> / ecosystems are likely to need to make distinctions based on similar
> semantic differences.
> 
> I posit that the distinction between those documents is the same as (or
> at least parallel to) the distinction between the 'thing' and the
> 'authority' in the lightweight abstraction layer.
> 
> I posit further that the lightweight abstraction layer is needed to
> express the difference between these documents:
> 
> http://id.loc.gov/authorities/names/no2008000433.html
> http://id.loc.gov/authorities/names/n79065871.html
> http://viaf.org/viaf/182132891/
> http://viaf.org/viaf/155934344/
> http://viaf.org/viaf/179020116/
> http://catalogo.bne.es/uhtbin/authoritybrowse.cgi?action=display&author
> ity_id=XX437257
> http://www.gutenberg.org/ebooks/5#bibrec
> http://www.wikidata.org/wiki/Q11698
> ...
> 
> Some of us may choose to banish some of those documents from the
> systems under our purview, but without the ability to express the
> differences and reason about them, we'll be unable to do so in an
> automated fashion based on BIBFRAME.
> 
> For example, we have a subject classification called Ngā Ūpoko Tukutuku
> http://mshupoko.natlib.govt.nz/mshupoko/index.htm It's entirely
> possible that we'd accept NŪT metadata from sources which we'd not
> normally accept LCSH metadata from.  Being able to express that in
> BIBFRAME opens the door to automated rule-based acceptance of such
> metadata, across a group of libraries.
> 
> Such a rule might be "When considering an authority for import, IF the
> authority refers to an entity that we already have AND we don't have
> NŪT for the entity AND the entity being considered does have NŪT for
> the entity, THEN import the authority." Such rules are hard /
> impossible to conceptualise without an 'authority' separate from the
> 'entity'.
> 
> [Note that I'm not suggesting we increase the scope of BIBFRAME to
> include rule-based workflows, just attempting to ensure that we can
> represent the condition clause of a rule in BIBFRAME]
> 
> ngā mihi
> stuart
> --
> Stuart Yeates
> Library Technology Services http://www.victoria.ac.nz/library/