On 7/31/14, 3:30 PM, Ford, Kevin wrote:
>> Of course, these have the "blank-node-+-label" problem again (still?).
> _:xx and _:yy do not need to be blank nodes. We've been using a lot of blank nodes in examples, but they do not need to be.
>

Kevin,

You are absolutely right, they do not need to be blank nodes. However,
my discovery of the issue with "bf:label" and blank nodes was on MARC
records that I ran through the BIBFRAME tool [1], not in hand-coded
examples. Obviously, BIBFRAME is not "done" so that tool is an
approximation of what BIBFRAME could be, but there is an unfortunate
reliance on blank nodes in its current state. This fact is somewhat
hidden by the use of rdf/xml, and ditto the email examples in turtle,
since blank nodes basically disappear in these notations. The proof of
the pudding is in the triples. Here is a segment of real BIBFRAME
instance data (as transformed from MARC by the BF tool, then converted
to turtle and triples using rapper):

**RDFXML:

<bf:publication>
   <bf:Provider>
     <bf:providerName>
       <bf:Organization>
         <bf:label>University of Michigan Press</bf:label>
       </bf:Organization>
     </bf:providerName>
     <bf:providerPlace>
       <bf:Place>
         <bf:label>Ann Arbor</bf:label>
       </bf:Place>
     </bf:providerPlace>
     <bf:providerDate>1995</bf:providerDate>
   </bf:Provider>
</bf:publication>
</rdf>

**turtle:

     bf:publication [
         bf:providerDate "1995" ;
         bf:providerName [
             bf:label "University of Michigan Press" ;
             a bf:Organization
         ] ;
         bf:providerPlace [
             bf:label "Ann Arbor" ;
             a bf:Place
         ] ;
         a bf:Provider
     ] ;

** triples

<http://bibframe.org/resources/cYO1404049290/3033010>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://bibframe.org/vocab/Work> .
<http://bibframe.org/resources/cYO1404049290/3033010>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://bibframe.org/vocab/Text> .
_:genid1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://bibframe.org/vocab/Provider> .
_:genid2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://bibframe.org/vocab/Organization> .
_:genid2 <http://bibframe.org/vocab/label> "University of Michigan Press" .
_:genid1 <http://bibframe.org/vocab/providerName> _:genid2 .
_:genid3 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<http://bibframe.org/vocab/Place> .
_:genid3 <http://bibframe.org/vocab/label> "Ann Arbor" .
_:genid1 <http://bibframe.org/vocab/providerPlace> _:genid3 .
_:genid1 <http://bibframe.org/vocab/providerDate> "1995" .
<http://bibframe.org/resources/cYO1404049290/3033010>
<http://bibframe.org/vocab/publication> _:genid1 .

The blank nodes become much more visible.

Many of the examples that we've seen on these recent threads don't
actually represent "running code," or at least I couldn't transform any
of them using tools that I have. I know this is a discussion, not a
coding session, but I think it would be helpful to do a sanity check
regarding what we are discussing by creating some working examples.
It'll provide a more realistic basis for discussion.

Personally, I'd like to see BIBFRAME move away from the use of blank
nodes wherever possible, and so I'd like to see examples that don't use
them.

kc
[1] http://bibframe.org/tools/transform/start

--
Karen Coyle
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m: 1-510-435-8234
skype: kcoylenet