Someone in DERI brought back a set of Semantic Web fridge poetry magnets from a workshop! A joyous occasion for all SemWeb nerds, and there are plenty of those in DERI.

deriblog, semanticweb | No Comments »

I’m still very much interested in the topic of analysing usage of linked data sites. To that end, an interesting question to ask is what kinds of agents access a linked data site. And here, apart from the usual categorisation into bots, browsers and such, it makes sense to differentiate between semantic and non-semantic agents. Very loosely, we could say that

Semantic agents are agents which are aware of RDF data and actively request it.

To know whether or not an agent requests RDF, we could look at the header of an individual HTTP request and check if the agent had specified Accept: application/rdf+xml. However, the Apache server log files unfortunately don’t tell us anything about the request header. Luckily though, there is an indirect way of finding out about this. If our linked data site uses best practice content negotiation and 303 redirects, we can look at pairs of requests in the log files. E.g., the Semantic Web Dog Food site uses a particular URI pattern for resources and their HTML and RDF representations. E.g.:

http://data.semanticweb.org/organization/deri-nui-galway
http://data.semanticweb.org/organization/deri-nui-galway/html
http://data.semanticweb.org/organization/deri-nui-galway/rdf

If the plain URI is requested, the server will either redirect to the HTML or the RDF representation, based on what was specified by the agent. Therefore, if we find a request for a plain URI and a request for the corresponding RDF URI, from the same IP address and the same agent, within a short time frame (e.g. 5 seconds), then we can infer that the agent had requested application/rdf+xml and can therefore be classified as a semantic agent.

90.21.243.141 - - [06/Oct/2008:16:07:58 +0100] "GET /organization/vrije-universiteit-amsterdam-the-netherlands HTTP/1.1" 303 7592 "-" "rdflib-2.4.0 (http://rdflib.net/; eikeon@eikeon.com)"
90.21.243.141 - - [06/Oct/2008:16:08:02 +0100] "GET /organization/vrije-universiteit-amsterdam-the-netherlands/rdf HTTP/1.1" 200 45358 "-" "rdflib-2.4.0 (http://rdflib.net/; eikeon@eikeon.com)"

The example above shows this: the “rdflib.net” agent requested the plain URI .../organization/vrije-universiteit-amsterdam-the-netherlands and was 303 redirected to .../organization/vrije-universiteit-amsterdam-the-netherlands/rdf a few seconds later. From this we can automatically infer that “rdflib.net” is a semantic agent.

A list of 423 semantic agents found in this way for the dog food site from 10/2008-10/2009 is here. Looking at the list, we can find a lot of agents that are clearly “semantic”, such as the “SindiceFetcher” or a SIOC browser. However, most of them are actually not what I would normally consider “semantic”, such as hordes of “Mozilla”-branded agents or dodgy looking bots. More research is awaiting…

deriblog, linked data, semanticweb | No Comments »

Bob DuCharme points out nicely how much the Web of Linked Data has grown in the past year by comparing to versions of Richard Cyganiak’s LOD cloud diagram. It looks pretty impressive when you compare the two versions side by side!

deriblog, linked data, semanticweb | No Comments »

I don’t announce every new addition to the Semantic Web Dog Food Server, but this is a big one: based on the data available from EPrints, we managed to get information about papers and authors for the upcoming WWW2009 in Madrid up as linked data on the dog food server. You can get all the papers, authors and their affiliations, all nicely integrated with the rest of the dog food data from other conferences. You can start start browsing here or get a dump of the data. Enjoy!

conference, deriblog, linked data, semanticweb | No Comments »

Last week we organised a second VoCamp – a grass roots, BarCamp-style workshop for creating Semantic Web vocabularies – in Galway. The setup was much like the first one in Oxford: we as the organisers provided the room and coffee breaks, but otherwise only set a very basic schedule (start-coffee-lunch-coffee-wrapup). The real action was provided by the delegates, who divided up into groups according to interests and worked away. On several occasions throughout the two days we all came together again and every group had the chance to report on their progress, discuss problems with all VoCamp delegates, etc. It was all very relaxed and productive, and with an interesting mix of people. Apart from a good crowd from DERI, there were people from Talis, Yahoo (Peter Mika was luckily able to make it) and Edinburgh. Some people even came from as far as Germany and Florida!

All the different groups and their results can be found on this wiki page, so I’ll just mention a few things here, such as vocabularies for meeting minutes, calls for papers or real estate (not forgetting the very important Ear Worm vocabulary), more work on a SW starter pack, discussions and work on Microformat-RDF mappings and RDFa in Drupal.

Luckily Galway was on its best behaviour – I think it didn’t rain at all during the two days. Looking forward to more VoCamps in other places soon!

conference, deriblog, drupal, rdfa, vocamp | No Comments »

So, ISWC2008 is over and I’m back in Galway. What did I learn this year?

• There are more and more Semantic Web applications out there, and they are getting slicker and more user-friendly every year. The demo and poster session and the Semantic Web challenges clearly showed that. Some highlights were probably paggr (semantic widgets) by Benjamin Nowack and several different apps that make use of mobile technologies (on the iPhone, no less). Incidentally, those two also won the first and second prize in the challenge (Benjamin won this for the second time already, after having won with CONFOTO (seems to be offline at the moment) at ISWC2005.
• Interestingly for me, a lot of people are working on solutions to make SPARQL-querying more accessible to end users. There is our own work on a SPARQL builder component for Konduit, there is the web-based graphical interface NITELIGHT, and some cool SPARQL extensions by Benjamin Nowack (again!). While those were all presented during the poster session, I also talked to some other people in the coffee breaks who told me about their work in this area – this clearly seems to be an area where a lot of developments and improvements are going to surface soon!
• OpenCyc – this is of course not really a new development, but after having attended the tutorial of using OpenCyc for the Semantic Web, I’m starting to think that their ontology and knowledge base are, at the very least, a very interesting point of reference for linked open data. Those guys have worked on their ontologies for a long time, and a lot of reasoning technology is already in place. Therefore, if we hook up our linked data to (Open)Cyc terms, the hope is that we can finally have the inferencing magic that people are dreaming of for the Web.
• And finally, to come to the title of this post. I learned the hard way this year that one cannot put enough effort into advertising one’s work and also oneself. I think Richard and I did a pretty good job with the conference metadata this year, and set up a very nice site with a lot of interesting functionality for developers and conference attendees. Unfortunately, we didn’t spend an equal amount of work on making the people at the conference aware of that, with the result that e.g. way too few knew that there was an option to discuss papers online and make those discussion become part of the metadata about the paper. Also, to my surprise, some people even didn’t seem to know that I had been acting as metadata co-chair at all. Note to self: be more proactive next year.

conference, deriblog, semanticweb, travel | No Comments »

Hooray, the spanking new Semantic Web Dog Food site is finally ready for prime time at http://data.semanticweb.org! The site has been the central repository for conference metadata (people, papers, talks, organisations, etc.) from the major Semantic Web conferences (mainly ISWC and ESWC) in the past years, but so far has lacked a unified, cross-conference interface. Also, because different people had been responsible for generating the data for different conferences, the dataset wasn’t really as well interlinked as it could have been.

Now, with the help of funding from SWSA and the Nepomuk project, Richard Cyganiak, research intern Venkatram Yadav and me have managed to do a lot of data-cleaning and aligning and redo the whole site as a module on top of the Drupal CMS, with the result that everything is now a lot nicer looking, more user friendly, better interlinked and generally speaking cooler. Thanks a lot also to Stéphane Corlosquet, our local Drupal guru here at DERI, who helped us out with a lot of tricky Drupal questions.

Apropos Drupal: There is an interesting discussion going on at the moment in the Drupal community to add RDF export functionality to the Drupal Core system. What it means is basically exporting the Drupal DB as RDF (SIOC, FOAF, etc.). Somehow, our approach is the exact opposite – we export an RDF-DB through Drupal! Both approaches put together in a meaningful way would probably result in a very cool end product!

So, what can the Dog Food site do for you? Here is a list:

• Browse thousands of people, papers and organisations in your Web browser, …
• … or in a linked data browser – it’s all linked data!
• SPARQL to your heart’s content, making use of the named graphs we have established for each event in the database.
• To support your SPARQL needs, you can also use the snorql tool on the site.
• Comment and discuss each paper. All papers and comments are good citizens of the SIOC-osphere!
• Do a full-text search on the data on the site.
• Enjoy eye-candy like the map of all organisations in the repository (provided we have their geo-coordinates).

conference, deriblog, drupal, semanticweb | 2 Comments »

I just came back from the first VoCamp, held at Wolfson College in Oxford. It was the first in what will hopefully become a series of small, hands-on, community-driven events where people get together to build and work on vocabularies and ontologies for the Semantic Web. Peter Mika had a nice blog post recently on why such activity is badly needed.

The whole event was pretty organic and loosely organised. Compared to big, official events with lots of pretty boring talks (not saying that _all_ talks are always boring), VoCamp was refreshingly fun and engaging. I actually had the feeling that I was doing something useful. Ad-hoc groups formed on the spot, working on varied topics such as an IRC vocabulary, a whiskey ontology, something which could be called a “vocabulary starter pack for SemWeb newbies”, an evidence ontology, bio-med vocabularies, etc. The idea is that we will have a number of VoCamps in rapid succession (the next one will be in November here in Galway), and so, even though probably none of the individual topics will have enourmous impact just now, I think VoCamp can definitely create a lot of momentum over time.

On Thursday, we planned to take the opportunity to join the Oxford SWIG meeting, but unfortunately there didn’t seem to be a lot of Semantic Web interest just that evening in Oxford. However, I did manage to say hello to Kal Ahmed of TM4J (Topic Maps) fame!

conference, deriblog, semanticweb, travel, vocamp | 1 Comment »

(Wow, I havn’t been blogging for months…)

Last week I attended really fun and interesting games research workshop at HUMLab, Umeå University in Sweden. Originally, this workshop started out as a get-together of the Truants World of Warcraft guild, but then quickly turned into an actual workshop, with presenters coming from all over Europe and even the US. Since everybody except me came from an arts and social sciences background – games and media researchers, sociologists, history, ethnology – this was an experience which was rather different from the IT conferences I usually attend.

The schedule was a good mix of lectures and hands-on activities, ranging from Games as Social Systems, Gaming and the Gender Gap, Leadership to a Machinima Workshop. The highlight was probably the presentation of star guest Mia Consalvo, who talked about The Cultural Practices of Cheating in Digital Games. I found all of the lectures really interesting and engaging (a welcome change from some of the dry and boring technical talks I’ve seen elsewhere), even though I must admit that I probably lack a lot of the background knowledge. In revenge, I was able to torture an audience of arts researchers with a really technical talk about a World of Warcraft Mashup, including topics such as the internals of WoW addons and Semantic Web and other Web<->Game mashups, such as an Ultima Online Hack or RDFRoom. Actually, this mashup is something I will also present at the upcoming Semantic Web Scripting Workshop at ESWC2008. More about this soon, stay tuned…

I just have to add that, going very well with the topic of the workshop, the social event was a match of laser tag to the death! Basically a three team Warsong Gulch with laser weapons (And a dinner, of course…)

conference, deriblog, travel | 1 Comment »

Shift (as well as Kante and Knoten) have been available as source for a while now, but installing from source is not really a lot of fun if you just want to try it out.
So, now I finally got around to putting together an installer package for Shift, that will just install the binaries on your computer! It contains the Shift application itself, as well as three plugins (AddressBook, iCal and BibDesk). So, no more excuses – just download the installer, install Shift, and start creating RDFa! :)
When I get the time, I will put together a proper readme file. In the meantime, I hope you will find Shift self-explanatory.

Oh, and please send plenty of bug reports.

deriblog, rdfa, semanticweb, shift | No Comments »