- From: Tantek Çelik <tantek@cs.stanford.edu>
- Date: Fri, 22 Nov 2013 08:41:46 -0800
- To: Ivan Herman <ivan@w3.org>
- Cc: Tantek Çelik <tantek@cs.stanford.edu>, Jeni Tennison <jeni@jenitennison.com>, HTML Data Task Force WG <public-html-data-tf@w3.org>
Ivan, Did you just send this reply or did it just get copied to this list? http://lists.w3.org/Archives/Public/public-html-data-tf/2013Nov/0001.html Did you post it because there are thoughts around updating this document with errata? Thanks, Tantek On Tue, Dec 20, 2011 at 12:23 AM, Ivan Herman <ivan@w3.org> wrote: > > On Dec 20, 2011, at 02:55 , Tantek Çelik wrote: > > On Mon, Dec 19, 2011 at 03:45, Ivan Herman <ivan@w3.org> wrote: > > Jeni, > > > I am beginning to get out of my post-surgery torpor, although only very > slowly. > > > Best wishes for a speedy recovery Ivan! > > > Thanks! > > > > But I did go through the document today, and have noted a bunch of comments, > see them below. There is no priority order, I just made the notes as I read. > I am sure there are more issues coming up, but this may be a good start. > > > And thanks... > > > Ivan > > > In the introduction: I wonder whether it is worth emphasizing that adding > structured data to HTML was also pioneered by the Semantic Web community in > an attempt to bridge the world of documents and of data on the web. Many > data publishers use their HTML pages as an alternative syntax to publish > their data (using RDFa); examples include the authorities' pages of the > Library of Congress, or DBPedia. (Yes, I know, I am biased!) > > > Ivan, I'm not sure what you mean by "pioneered" in this context. > > > Tantek, you are right, it was not the right choice of words. In a sense, my > reaction was more to the fact that the current text has a very strong bias > towards the search engine usage. And the usage of HTML as a vehicle to bind > to Linked Data has been a strong motivation in the past few years. That is > all... > > [snip] > > > Actually, if we go there, it may be worth emphasizing that microformats are > language agnostic in the sense that they are bound to the usage of CSS only > (ie, microformats could be used in SVG, too). > > > To be clear, microformats make use of the *HTML* class attribute, but > > can work directly in any XML language with a class attribute (like > > SVG, MathML), or XML without class attributes by embedding XHTML. > > > > Just out of curiosity (nothing to do with the current issues): does the > microformat definition strictly entail that it must be a class attribute of > HTML? I always considered to be more liberal and workable, as you say, with > MathML and SVG out of the box... > > > > In the introduction: it may be worth emphasizing that microdata has been > defined for HTML5 only. Ie, if authors care about validation, they should > not used microdata with, say, XHTML 1.0. > > > I realise you come back to this issue in section 2, but the introduction > really sets the tone... > > > ----- > > > 1.1 Scope: is it correct that one can add RDF/XML into a script element? I > must admit I have never seen that in practice and is fairly problematic in > XML point of view (unless CDATA is used). I think it would be safer not to > refer to that. > > > Yeah this has been tried in the past (at least with XML in the defunct > > StructuredBlogging effort) and is should be considered an obsolete > > technique not worthy of an intro. > > > I agree. > > > If you're looking to document dead-end web data efforts for historical > > purposes, there's plenty more to add to the list, e.g. > > StructuredBlogging, Google Base, and most recently CommonTag. > > > > Section 2.1.1: I am not sure we should list it here, but maybe: a particular > issue with microformats is that the vocabularies use the @class attribute > value. > > > This may clash with the class attribute value as used in the CSS files that > are, eg, part of a corporate publishing environment. > > > This is a known documented issue for microformats-1 style microformats: > > > http://microformats.org/wiki/microformats-issues#class-collisions > > > Is it the purpose of this document to list issues with all approaches? > > If so, there's plenty more. > > > > > Good question. I let Jeni decide on that, as editor of the document. You are > right that we have to avoid giving the impression of arbitrary choices. > > > Authors should carefully check this before they decide to use microformats, > otherwise they are in for major surprises in the way their page will be > rendered... > > > Ivan, do you know of specific examples where this has occurred? > > > Please provide them so I can add them to the documentation of the > > issue on our microformats wiki. > > > Absent such documentation, I don't see why this would be worthy of a > > warning in this document. > > > Honestly: not in my personal experience. I have not done any extensive > search either. However, interestingly, this is one of the issue Google > claims to have ran into for rich snippets. Yes, this is what the US law > practice calls 'hearsay', ie, you can object to it:-) > > > > An additional issue is that microformats may require, say, the usage of the > <abbr> element and this may clash with accessibility considerations of a > particular publishing environment... > > > This issue has been long since (2+ years) addressed and resolved with > > the microformats value-class-pattern. > > > http://microformats.org/wiki/value-class-pattern > > > > > .... which may be worth noting then? (Not sure where the borderline is.) > > > Still on 2.1.1: If the publishers wants to make use of Linked Data, for > example, by making it easy/possible to link the data in the page to other > linked data vocabularies easily then, probably, RDFa is a much better > choice, simply because it is inherently bound to RDF. > > > I think this merits explanation, and I don't accept "inherently bound > > to RDF" as a good argument here. > > > As long as a syntax can produce properties and data bound in URLs > > (which I believe is possible with all the current syntaxes being > > discussed in this TF), isn't that all that's necessary for Linked > > Data? > > > > Well, I do not want to go into a long discussion on what Linked Data is; > this is not the right place. Yes, URI-s are important. But, to be a little > bit more orthodox at this point, the issue is whether the data in a given > vocabulary can or cannot be mapped onto RDF through a clearly specified > manner. While this is not an issue for RDFa, there are issues, essentially > per vocabulary, both for microformats or for microdata. AFAIK, and you may > correct me, not all microformats vocabularies give clear definitions on what > URI-s to use, for example; and the microdata vocabulary specification > requirements are even more convoluted in this respect. Ie, at least for some > vocabularies, there might be issues that the authors should know about. > > Also, there is a very dynamic scene on the linked data world in the > definition of various vocabularies. Some of those (bibliography, music, > dublin core, to take just three) have a clear usage within an HTML page, > too. Those can be used directly from within RDFa, it is a bit complicated to > do it with other syntaxes (even if the vocabulary itself is simple, like DC) > because it needs an extra mapping phase to those syntaxes. > > > Still on 2.1.1: what about datatypes? If a vocabulary requires the usage of > datatypes then... well, RDFa is the only one handling that. That being said, > it may be a very special case that we may not want to address here (and I > know it is addressed elsewhere.) > > > What do you mean for a vocabulary to "require the usage of datatypes"? > > > That the range of a property is defined to be a of a given datatype. > > > In microformats experience, we've never found a need to "require" a > datatype. > > > You are right that the word 'required' is wrong. What I meant is what is > above. > > I just picked one vocabulary, that has clearly its possible role on a web > page, namely the music ontology: > > http://www.musicontology.com/ > > that refers to xsd:int and others for a number of its properties. > > Of course, it is perfectly possible, from a SW point of view, to produce > data that does _not_ explicitly defines, say, a <span>10</span>, to be an > integer; after all, a range specification is a license to infer and not a > restriction. But practice is that authors may want to reinforce this using > the datatype. If that is intended then, well, we may have a problem. > > > On the contrary, the more such requirements were attempted, the higher > > the barrier, or the lower the data quality as authors get it wrong. > > > If anything, we should say something like: > > > "Avoid vocabularies that require the use of datatypes." > > > I think such a statement is too restrictive, and I would not agree with > that. See my example above. 'Watch out' instead of 'Avoid' might be > better... > > [snip] > > > > On Dec 11, 2011, at 18:22 , Jeni Tennison wrote: > > > Hi, > > > I've pulled together much of the documentation from our wiki into a single > document, at: > > > https://dvcs.w3.org/hg/htmldata/raw-file/default/html-data-guide/index.html > > > Please take the time to read this as it is the main product of this Task > Force, and raise any comments here. > > > > Jeni, given the extensive feedback from Ivan (and the comments I and > > myself have made), the one general item of feedback I'd say is: > > > Perhaps it's better to just keep this document on the wiki for now, to > > enable/encourage more collaborative iteration/updating - especially > > with minor fixes. > > > hg is just less accessible/usable than MediaWiki. > > > A bit. It does require hg knowledge, that is:-) > > > If you're looking to generate something that looks like a W3C note, > > perhaps it would be better to simply auto-generate such a note from a > > specific wiki page. > > > I am not sure we have tools to do that (would be good). Ie, I am a little > bit afraid that this would mean an extra load on Jeni at the end... > > Thanks! > > Ivan > > > > After all, most of the semantics should directly > > map right? > > > Thanks, > > > > Tantek > > > -- > > http://tantek.com/ - I made an HTML5 tutorial! http://tantek.com/html5 > > > > ---- > Ivan Herman, W3C Semantic Web Activity Lead > Home: http://www.w3.org/People/Ivan/ > mobile: +31-641044153 > FOAF: http://www.ivan-herman.net/foaf.rdf > > > > >
Received on Friday, 22 November 2013 16:42:54 UTC