W3C home > Mailing lists > Public > public-rdf-in-xhtml-tf@w3.org > July 2007

Re: Determination of subjects/objects (was: ISSUE-42)

From: Dan Brickley <danbri@danbri.org>
Date: Mon, 30 Jul 2007 18:03:35 +0100
Message-ID: <46AE19E7.3050404@danbri.org>
To: Knud Hinnerk Möller <knud.moeller@deri.org>
Cc: Manu Sporny <msporny@digitalbazaar.com>, public-rdf-in-xhtml-tf@w3.org

Knud Hinnerk Möller wrote:
> Hi,
> 
> Am 30.07.2007 um 17:15 schrieb Manu Sporny:
> 
>> Mark Birbeck wrote:
>>> I haven't had a chance to re-read this thread, so I'm not going to say
>>> anything on the substance. But if you don't mind, I'd like to comment
>>> on a recurring theme, which seems exemplified by the following:
>>>
>>>> I have a visceral problem with about="_:", and that is that it makes
>>>> bnodes explicit, which I really don't want to do to HTML authors. That's
>>>> just too much RDF.
>>>>
>>> I don't see the need to 'protect' authors who are not familiar with
>>> RDF from RDF constructs that they will never use. If someone from the
>>> RDF community thinks this is useful, and _if_ we can support it
>>> without it getting in the way, then why not?
>>
>> Constructs such as "_:" are scary to non-RDF folks. :) From a
>> historically RDF-unaware perspective (mine), I stared at the "_:"
>> construct and had no idea what it does. It is not very intuitive.
>>
>> Even having seen it, I haven't taken the time to look up what it means.
>> It will probably make sense when I do, but to somebody that is not
>> trained in CS/EE/ECE/etc., this is a scary construct. To the lay web
>> page author, it is syntactic gibberish.
>>
>> There is already a very strong feeling in the Microformats community
>> that RDFa is far too complicated for most web page authors. The last
>> thing most of them want to learn is yet another language syntax for
>> describing what they see as "corner-cases of the language".
>>
>> I see your argument: If they aren't going to use it, and if it doesn't
>> cause any harm, then why not put it in there?
>>
>> I would argue that you shouldn't put things in there that aren't
>> absolutely necessary. It complicates the RDFa specification. If there is
>> a need in the future, you can always add it in a later revision.
> 
> I would really argue to have bnodes in RDFa: I know they are very 
> unpopular, and vocabularies like FOAF now recommend against using them. 

No they don't :) well, foaf in particular...

I put a #me into the FOAF spec example, that's all.

RDF is a language for representing and aggregating partial information 
into a greater whole. Sometimes that information lacks statements, 
sometimes those statements are missing well known identifiers. Sometimes 
the things the statements are about don't even have well known identifiers.

There are things in FOAF such as isPrimaryTopicOf which are designed to 
help people live in such a world. But there is nothing FOAF or other RDF 
vocabs can do to get away from the basic fact: informational is not 
universally and evenly available. RDF authors do not have a godlike 
access to every fact and every identifier they might need. And so RDF 
data is inevitably a lossy, gappy thing. Sometimes missing statements, 
sometimes missing URIs. Because RDF is written by people, and people do 
not know everything. If they did, why would they bother exchanging RDF 
files with each other? :) And so we have bnodes.

That said, "_:" in RDFa worries me too.

Dan
Received on Monday, 30 July 2007 17:03:45 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Tuesday, 8 January 2008 14:15:08 GMT