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Re: Draft Review of the ITS 2.0 draft document

From: Ivan Herman <ivan@w3.org>
Date: Sat, 24 Aug 2013 08:10:22 +0200
Message-Id: <66B979CA-EFF7-440D-996B-0052B0C9D82C@w3.org>
Cc: W3C RDF WG <public-rdf-wg@w3.org>, Felix Sasaki <fsasaki@w3.org>
To: Pat Hayes <phayes@ihmc.us>
That is a good point, but it may still be good for the records of the ITS WG to, at the minimum, share our opinion without requesting a change. The ITS WG may then decide to contact, eg, the TAG if they want... The problem is that I do not really see which group owns this thing.

Actually... we are not completely out of this. After all, the concepts document does talk about fragments, ie, we do go beyond a purely opaque IRI...

Note sure. 

Ivan

---
Ivan Herman
Tel:+31 641044153
http://www.ivan-herman.net

(Written on mobile, sorry for brevity and misspellings...)



On 24 Aug 2013, at 06:19, Pat Hayes <phayes@ihmc.us> wrote:

> Ivan
> 
> While I sympathise with, and share, your discomfort, I don't see that this is an issue particularly for RDF to comment upon. RDF, as you note, treats IRIs as opaque, so this entire discussion seems irrelevant to RDF-WG. Maybe some other WG, or the TAG, should be asked to take up this issue with ITS WG ?
> 
> Pat
> 
> 
> On Aug 23, 2013, at 5:57 AM, Ivan Herman wrote:
> 
>> As recorded as an action (wait, it was not recorded on the call because tracker got confused by several ivan-s:-) I reviewed the ITS 2.0 document, as requested by the ITS WG via Felix Sasaki[1]. The section that is relevant for this Working Group is the mapping to an external ontology, called NIF[2]. Actually, the details of that ontology are also not relevant for this Working Group; the issue is to map the attributes set on the textual content of an HTML (or XML) document into RDF.
>> 
>> To take the example of the document:
>> 
>> <html><body><h2 translate="yes">Welcome to <span 
>> its-ta-ident-ref="http://dbpedia.org/resource/Dublin" its-within-text="yes"
>> translate="no">Dublin</span> in 
>> <b translate="no" its-within-text="yes">Ireland</b>!</h2></body></html>
>> 
>> the goal is to produce a set of RDF statements of the form:
>> 
>> <URI_TO_IDENTIFY_A_TEXT_PORTION>
>>  nif:property1 value1;
>>  nif:property2 value2;
>>  nif:prop <URI_TO_IDENTIFY_A_TEXT_POSITION>
>>  ...
>> 
>> The really interesting question is how to define the two URI-s <URI_TO_IDENTIFY_A_TEXT_PORTION> and <URI_TO_IDENTIFY_A_TEXT_POSITION>, where, say, the first should somehow refer to "Welcome to Dublin Ireland!" and the other should tell the world that this text is within the <h2> element of the file.
>> 
>> The current mapping uses the following two URI-s
>> 
>> <http://example.com/exampledoc.html#char=0,29>
>> <http://example.com/exampledoc.html#xpath(/html/body[1]/h2[1])>
>> 
>> although it is quite obvious what these are for, I sense some sort of a problem with these. We may end in a rathole, but...
>> 
>> - We refer to IRI-s in our concept document: RFC3987
>> - IRI-s map to URI-s: RFC3987
>> - What RFC3987 says about fragments is:
>> 
>> "The fragment's format and resolution is therefore dependent on the media type [RFC2046] of a potentially retrieved representation, even though such a retrieval is only performed if the URI is dereferenced.  If no such representation exists, then the semantics of the fragment are considered unknown and are effectively unconstrained."
>> 
>> The way I translate is that if I want to have a proper URI, where I expect the media type to be BLA, then the fragment ID should somehow be defined for BLA. Although RDF regards IRI-s as opaque, I would still feel uneasy to do otherwise.
>> 
>> Looking at the URI-s above
>> 
>> - The 'char' fragment is defined by rfc 5147, but is defined for text/plain only. ITS talks about XML and HTML, ie, talks about resources whose media types are definitely _not_ text/plain
>> - The xpath fragment id is fine for XML. But it is not defined for text/html and, knowing how XML is frown upon by the HTML WG, I do not expect that to ever change.
>> 
>> In view of this, I do not feel comfortable with the choice of the mapping. The URI-s are not dereferenceable, neither are they correct...
>> 
>> That being said, I may be too picky and we could let this go, also considering the fact that this section is _not_ normative in ITS.
>> 
>> I had some discussion with Felix and also with Sebastian Hellmann, who is the author of NIF; one proposal I had was to use a URI of the form
>> 
>> http://www.w3.org/its?resource=http://example.com/exampldoc.html&char=0,29 
>> 
>> which, if some simple service is provided, can provide some simple information back, and is ok as a URI. I think that would be acceptable to them. But again, this WG may decide that I am just way too pedantic...
>> 
>> Ivan
>> 
>> P.S. It is of course possible to radically change the mapping with some blank nodes in the middle to avoid the issue...
>> 
>> [1] http://lists.w3.org/Archives/Public/public-rdf-wg/2013Aug/0000.html
>> [2] http://www.w3.org/TR/2013/WD-its20-20130820/#conversion-to-nif
>> 
>> ----
>> Ivan Herman, W3C 
>> Home: http://www.w3.org/People/Ivan/
>> mobile: +31-641044153
>> FOAF: http://www.ivan-herman.net/foaf.rdf
> 
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Received on Saturday, 24 August 2013 06:10:50 UTC

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