- From: Nathan <nathan@webr3.org>
- Date: Fri, 17 Jun 2011 21:17:56 +0100
- To: Semantic Web <semantic-web@w3.org>, Linked Data community <public-lod@w3.org>
have been afc/ill for a while and after catching up today I've noticed there's been quite a bit going on over the last month, lots of nice meaty posts to the list, seems like a good chance to embrace some things and see what can be done moving forwards - so a few questions and comments: schema.org / microdata: RDFa is to RDF as Microdata is to [____]? It seems conceivable that people may start using these common schemas from schema.org as data schema's behind the public interface in data stores - it would be nice to have a framework in there to save a few years of people repeating the same code and work. If we extract the microdata from an html document what is the data model, how does one save it? how does one transfer it out of context as raw data? OWL/RDFS is to RDF as [___] is to Microdata? OWL/RDFS for microdata? how does one validate data, for example domain, range and enumerables? microdata is rdf merged with rdfa cut down to size and given a classes and objects style found in many programming languages - this needs webized and abstracted out of html. Somewhat complimentary to Harry's comments, there's more to be gleaned from this than surface syntax and seo needs, to me at least the most interesting details are in how the schema's are constructed, many things to be noted and considered here - it's a common approach that most programmers will be familiar with - as above, and again, it needs webized. microdata @itemref - doesn't this look like blank node in a surface syntax? @itemid and @id will probably lead to confusion - if rdfa and microdata were both to leverage @id (in addition to html and javascript) then we'd have a low cost and high unification of approaches that would lend to the frag based many things described on one page approach that is ever so common. Consistency would be good in this department. @itemprop has a clever algorithm, but will probably lead to unexpected functionality, it's inconsistent. eg: <span itemprop="genre">Science fiction</span> <a href="../movies/avatar-theatrical-trailer.html" itemprop="trailer">Trailer</a> lot's of wasted data, consider "Bob Smith" in the following: <div itemscope itemtype="http://schema.org/Person"> <a href="bob.html" itemprop="url">Bob Smith</a> </div> and the use of alt, title - it's useful data that isn't utilized: <div itemscope> <img itemprop="image" src="google-logo.png" alt="Google"> </div> range-14: the "ambiguous 'like'" and the "comments on a post" are two very good cases to be focused on, in the first case, the question of "what is being liked?" is very interesting, some sites have already taken a far more fine grained approach to this, if you look at sites like reddit with karma for both posts and comments you can see a clear need, and it's a good use case to focus on, further if one were to consider an http friendly read write api for those comments, then I'd argue it quickly becomes clear that each comment would potentially need two identifiers, a hash one for microdata and linking to the comment in context, and another one for CRUDing the comment and linking to it out of context - there must be an easy to create pattern between something like /post#comment-id and /comment/id . the old arguments are well played out, and multiple approaches (see issue-57 document from JAR) are available - but the above two practical use cases will probably give the most long term benefit when addressed. scruffyness and diversity: David (Wood) recently mentioned "Neat vs Scruffy" which was a great point, and Kingsley has long since encouraged us to embrace the diversity of the web and look to translate from one format to another, and as Tim says, the web is an open platform that anybody can build on top of, thus we have an architecture that encourages diversity and innovation - it appears again to me that with schema.org and microdata we're being pointed in the direction people want to go, this raises many (potentially easy to address) questions, as I've listed above. Yes we can look to push RDF more, and convert microdata to rdf, try and get RDF and OWL up there to understand schema.org - no harm in that - but as I've mentioned before, some form of (simple) universal data could easily be designed on the back of this, and rdf, to offer something practical to the web masses that anybody can use, build on top of, and save lots of work around the globe. Quite some time ago the RDFa/Microdata thing was noted, and it was clear then that the two needed merged before too much weight went behind microdata and legacy issues meant it was hard to change, that time is past now, I'm aware that some efforts may happen in this department, but really I'd be looking to see what lessons can be learned for RDF here, before the same thing happens there two, as there's been a huge investment in the sem web stack, and a large corporate trio could easily rip the ground from underneath this relatively small community, may not happen, but there's a risk of it, and it does appear that there's a strong long term message of "rdf is too complicated, we like to do things like this [x]", the same message can be found in microdata, and ignoring it could be risky. apologies for being a bit quiet of late, and for the cruffyness of this mail - not been too well, trying to slowly get back in to things at the minute - hope to be back on form soon. best, nathan
Received on Friday, 17 June 2011 20:19:05 UTC