Re: Re 2: PROPOSAL to close ISSUE-37: Clarifying bnode explanation

<rant>

At the risk of sounding like... well... me, I have to say this is the 
MOST ABSURD discussion we have ever had in this working group.  And we 
have had some doosies.   You guys often discuss things that the rest of 
the world would perceive as 'how many angels will fit on the head of 
this pin?', but this is more like 'while the angels are on the head of 
the pin, how many of them are wearing blue socks?'  Honestly.... no 
one,  and I mean no one, is even going to read these examples.  Of the 
statistically small number of people who do actually read them, _no one_ 
is going to know or care that in some other specification there is some 
subtle definition that means these arbitrary identifiers might be 
changed into other arbitrary identifiers.  No one will care.

I'm not going to go all 'hixie' on your asses.  I don't do that.  But 
this needs to stop.  The document as it stands right now is fine.  It 
doesn't require any clarification.  The 10 people in the world who 
understand this stuff already KNOW that these identifiers are 
arbitrary.  The rest of us don't care.  What we care about is how to 
shoehorn some semantics into our HTML.  If you want to cover this at 
all, you should cover it in the RDFa API specification.  That's the 
place to say "and oh, by the way, just because the source says a bnode 
is called ':_shane' doesn't mean it will still be called that when you 
extract it - don't rely upon that."

</rant>

On 10/20/2010 3:15 PM, Mark Birbeck wrote:
> Hi Nathan,
>
> On Wed, Oct 20, 2010 at 8:04 PM, Nathan<nathan@webr3.org>  wrote:
>> Mark Birbeck wrote:
>>> However, nowhere do we say that in between the two serialisations
>>> (RDFa and Turtle) the data has been stored and re-serialised. And
>>> since nothing has happened in between those two serialisations then it
>>> would be *wrong* to have a mismatch in the blank node identifiers that
>>> are used in those two serialisations.
>> not really being pedantic, but the only way to get the Turtle from the RDFa
>> is to store and serialize it, so in reality anybody taking the example RDFa
>> and converting it to Turtle will see different bnode identifiers. In fact
>> about the only time the identifiers will ever presented as consistent, is in
>> this document.
> Now we really are going off-piste...why are you talking about getting
> Turtle from RDFa!
>
> Let's rewind...
>
> Look at the top of section 3.6:
>
>    RDF itself does not have one set way to express triples, since the
>    key ideas of RDF are the triple and the use of URIs, and not any
>    particular syntax. However, there are a number of mechanisms for
>    expressing triples, such as RDF/XML [RDF-SYNTAX-GRAMMAR],
>    Turtle [TURTLE], and of course RDFa. Many discussions of RDF
>    make use of the Turtle syntax to explain their ideas, since it is
>    quite compact. The examples we have just seen are already using
>    this syntax, and we'll continue to use it throughout this document
>    when we need to talk about the RDF that could be generated from
>    some RDFa.
>
> The point is straightforward; it effectively says that since RDF is an
> abstract syntax, we have no way to represent the triples generated,
> but as an approximation we will use Turtle.
>
> To put it a different way, what we said way back when this was written
> was: here's a *new* way of serialising RDF (RDFa), and the easiest way
> we can think of to explain it to you is to use an *old* way of
> serialising RDF (Turtle).
>
> So we certainly aren't 'converting' one serialisation to another, by
> parsing first.
>
>
>> The only reason the bnode identifiers are aligned in the examples is because
>> the group has chosen to show them that way for the sake of clarity...
> Yes...clarity...and the minor issue that otherwise the examples just
> simply wouldn't make sense.
>
>
>> ...thus it
>> appears perfectly reasonable to also state that bnode identifiers can't be
>> relied upon and show an RDFa-Turtle example pair where the bnode identifiers
>> aren't aligned, again for the sake of clarity.
> No...it makes no sense. The examples are *not* about round-tripping
> the triples, they are merely about trying to explain to people what
> triples would be generated from some mark-up.
>
> The issue you describe relates to *retrieving* triples that have been stored.
>
> Or if you prefer to think in terms of the abstract syntax, the issue
> is about moving from an RDF graph in which none of the bnodes have any
> names (since they are by definition anonymous), to a serialisation
> where they /do/ have names (i.e., bnode identifiers).
>
> At that point...yes, the identifiers can be anything.
>
> But to stress again, our examples have an RDFa serialisation followed
> by a Turtle serialisation only to help explain what's happening. We
> haven't moved to an RDF graph at all -- we've stayed at the level of
> serialisation, by moving from one to another.
>
>
>> The issue looks to be "clarifying bnode explanation" and I for one feel the
>> text Toby suggested, with both examples, does indeed clarify the explanation
>> of bnodes.
>>
>> Do you disagree?
> Vehemently. :)
>
> Regards,
>
> Mark
>
> --
> Mark Birbeck, webBackplane
>
> mark.birbeck@webBackplane.com
>
> http://webBackplane.com/mark-birbeck
>
> webBackplane is a trading name of Backplane Ltd. (company number
> 05972288, registered office: 2nd Floor, 69/85 Tabernacle Street,
> London, EC2A 4RR)

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