On Snake Oil

Greetings, from the shady corner of the marketplace, where dubious characters tell tales of substances with mystical properties, and push their wares on unsuspecting passersby…

Today I had the dubious privilege of being branded a snake oil salesman, on the grounds that my “boosting” of the Semantic Web isn’t backed up by adequate eating of my own Semantic Web dog food. Apparently neither my publications page, or any of my other pages on my site, have any “intelligent content tagging”, whatever that is (I assume this means RDFa).

If it does mean RDFa, then true, but this does completely overlook the RDF/XML on my site, which as a whole is built according to Linked Data principles. More galling is that the claim completely overlooks the work I’ve done in the Semantic Web community that kick-started a lot of the ongoing dog food activity at ESWC and ISWC  (this was not a lone effort by any means: Knud Moeller, Sean Bechhofer, Chris Bizer, Richard Cyganiak and many, many others deserve as much or more credit as I do for ensuring it continued, as will Michael Hausenblas and Harith Alani at ESWC2009). Just to rub salt into the wound, these inaccuracies are being propagated across the Web in other people’s blog comments, e.g. here.

I’d like to end with some insightful meta analysis or reflection on this, but unfortunately I need to get ready for a trip to the US to run a workshop on Visual Interfaces to the Social and Semantic Web and give two days worth of Linked Data tutorials. Hope I don’t get stopped at US customs with that consignment of snake oil πŸ˜‰ So, no great insights for now, just a copy of my response in case it ever disappears from the original site in a puff of smoke.



I would be the first to agree with you that the Semantic Web community has not always eaten its own dogfood to the extent that it should have. It was for exactly this reason that in 2006 I produced RDF descriptions of almost all aspects of the European Semantic Web Conference (http://www.eswc2006.org/rdf/) and coordinated the deployment of numerous Semantic Web technologies at the conference (http://www.eswc2006.org/technologies/). My aim was to learn about deploying these technologies in the wild, and feed back my findings (positive or negative) to the community. The results of my evaluation were published here: http://swui.semanticweb.org/swui06/papers/Heath/Heath.pdf

Regarding the production of RDF to describe Semantic Web conferences, there had been some small efforts in this direction at previous events, but nothing comprehensive. ESWC2006 changed that for good, and there have been RDF descriptions of all European and International Semantic Web conferences published ever since. This data has been published using an ontology that derives largely from the one I created for ESWC2006, with significant contributions along the way from others. There is now a regular position on the organising committee of these conferences for people charged with coordinating this effort for the event. Knud Moeller and I shared this role at ISWC2007, where we also reported back to the community on our efforts up to that point: http://iswc2007.semanticweb.org/papers/795.pdf. Many other people have contributed significantly along the way, and this combined effort has produced the repository of data at http://data.semanticweb.org/ to which RDF descriptions of ESWC2009 will also be added.

But as you point out, the institutions that promote the Semantic Web also need to put their money where their mouth is. Agreed. While I was a PhD student at The Open University’s Knowledge Media Institute, I argued for developer time to add RDF descriptions about all KMi members to the institute’s People pages (http://kmi.open.ac.uk/people/), and tutored the developers in how to apply their existing Web development skills to exposing Semantic Markup.

My PhD work included development of the reviewing and rating site Revyu.com (http://revyu.com/), which won first prize in the 2007 Semantic Web Challenge. I can’t speak for the judges, but my hunch is that a major factor in Revyu’s success in the Challenge stemmed from its strict adherence to the Linked Data principles (http://www.w3.org/DesignIssues/LinkedData.html), which have done so much to help people make the Semantic Web a reality. Revyu publishes human-readable (i.e. HTML) and machine-readable (i.e. RDF) content side by side, but humans won’t see this RDF (I assume this is what you mean by “intelligent content tagging”) unless they know where to look; this is the intended behaviour, and works according to the techniques described in the How to Publish Linked Data on the Web tutorial (http://linkeddata.org/docs/how-to-publish) that I co-authored with Chris Bizer and Richard Cyganiak.

My personal Web site follows the same principles and uses the same techniques. If you view the source of my homepage you will see a link tag in the header that looks like this:
<link rel=”meta” type=”application/rdf+xml” title=”RDF” href=”http://tomheath.com/home/rdf” />
This is the link that tells Semantic Web crawlers to look elsewhere for the semantic markup on my site, not in the human-readable HTML page where it might get broken if I tweak the layout. If we ever meet in person I will give you one of my business cards, which doesn’t give the address of my homepage – it gives my Web URI (http://tomheath.com/id/me); humans and machines can look up this URI and retrieve information about me in a form that suits them (i.e. HTML or RDF), and follow links in that HTML or RDF to other related information. In the words of Tim Berners-Lee, this setup is “the Semantic Web done right, and the Web done right”.

Yes, it’s unfortunate that my publications page doesn’t have an RDF equivalent; perhaps I’ve been too busy investing time and energy in initiatives that will have an impact beyond the scope of my own Web site? But either way, your comment that “nor any of his other pages (that I saw) uses any form of intelligent content tagging” just doesn’t stack up. Before you make these sorts of claims I would ask, reasonably and politely, that you show due diligence in looking thoroughly, and in the right places, for the semantic markup on my site. For anyone who is in any doubt that it’s there, click on the small “RDF META” tile on the right hand side of pages on my site.

I think it’s also reasonable to expect, if you’re truly interested in how the Semantic Web community is tackling this issue, that I might be given the chance to respond to your queries in advance of this article going out, as Adrian Paschke and Alexander Wahler were. I can only hope that this response helps provide a fuller picture of the situation, with respect to my efforts and those of the community at large.

Lastly, a technical point. We need to remember that the Semantic Web allows anyone to say anything, anywhere (I’m borrowing from Dean Allemang and Jim Hendler here). So, while RDF data about my publications may not be available on my own site yet, you can find pieces of the jigsaw at data.semanticweb.org, and if all conferences and journals published their proceedings/tables of contents in RDF, then my job would simply be to join the pieces together, and I wouldn’t be faced with manually updating my list of publications. OK, so we’re not there quite yet. Yes, there’s work to be done, but we’re trying.


2 Responses to “On Snake Oil”

  1. Andraz Tori

    I have to say the whole discussion is funny. Yes, most of semweb proponents actually aren’t working on projects affecting end-users.

    One thing you can do is use Zemanta + some platform that doesn’t kill RDFa, for example Movable Type. In that case, you will get automatic RDFa added for your in-text links.

    Or, if you want to help everyone on WordPress: convince WordPress developers not to strip RDFa markup from the posts, so all WordPress users will be able to easily insert RDFa into posts. πŸ™‚

    Andraz Tori, Zemanta

  2. Tom Heath

    Hi Andraz,

    I’d be inclined to agree with you that it was just funny, if it wasn’t quite such an ill-informed, skewed and rather personal article πŸ™‚

    Guess the best thing we can do is to continue to eat our own dog food; actions speak louder than words. To this end I’ve installed the SIOC plugin for WordPress, as I promised Uldis a few weeks ago.