SSSW Day 3

Yeah, sure, the Summer School for the Semantic Web is over for quite a while now, and here I started to blog about it daily, and didn't manage to get over the first three days. Let's face it: it was too much! The program was so dense, the social events so enjoyable, I couldn't even spare half an hour a day to continue the blogging. Now I want to recap some of my notes and memories I have of the second half of the Summer School. My bad memory be damned - if you want to correct something feel free to do so.

This day's invited speaker was Roberto Basili of the University of Rome. He sketched the huge field of natural language processing, and although he illustrated the possible interactions between lexical knowledge bases and ontologies, he nevertheless made a strong distinction between these two. Words are not concepts. "The name should have no value for defining a concept." This is like "Don't look into URIs" for HLT-people. He made a very interesting point: abductions will become very important in the Semantic Web, as they model human thinking patterns much closer than strict deduction does. Up until this day I was quite against abductions, I discussed this issue very stubbornly in Granada. But Roberto made me aware of a slightly different viewpoint: just sell abductive resolutions as suggestions, as proposals to the user - et voilà, the world is a better place! I will have to think abou this a bit more some day, but he did made me think.

The theoretical sessions and workshops today were packed and strenuos: we jumped from annotations to Semantic Web Services and back again. Fabio Ciravegna of the University of Sheffield's NLP-Group, who created tools like Armadillo and GATE, gave us a thorough introduction to annotations for the Semantic Web and the usage of Human Language Technologies in order to enhance this task. He admitted that many of the tools are still quite unhandy, but he tried to make a point by saying: "No one writes HTML today anymore with a text editor like Emacs or Notepad... or do you?"
All students raised their hands. Yes, we do! "Well, in the real world at least they don't..."

He also made some critical comments on the developments of the Semantic Web: the technologies being developed right now allow for a today unknown ability of collecting and comining data. Does this mean, our technologies actually require a better world? One with no secrets, privacy and spam, because there is no need for such ideas? Is metadata just adding hay to the haysteak instead of really finding the needle?

John Domingue's Talk on Semantic Web (Web) Services was a deep and profound introduction to the field, and especially to the IRS system developed by the KMi at Open University. He was defending WSMO valiantly, but due to time constraints pitily skipped the comparision with OWL-S. But he motivated the need for Semantic Web Services and sketched a possible solution.

The day ended in Cercedilla, where we besieged a local disco. I guess the people were hiding, "watch it, them nerds are coming!" ;) The music surprisingly old - they had those funny vinyl albums - but heck, Frank Sinatra is never outdated. But the 80s certainly are...

SSSW Day 2

Natasha Noy gave the first talk today, providing a general overview on Mapping and Alignment algorithms and tools. Even though I was not too interested in the topic, she really caught my interest with a good and clean and structured talk. Thank for that! After, Steffen Staab continued, elaborating on the QOM approach to ontology mapping, having some really funny slides, but, as this work was mostly developed in Karlsruhe I already knew it. I liked his appeal for more tools that are just downloadable and usable, without having to fight for hours or days just to create the right environment for them. I totally agree on that!

The last talk of the day was from Aldo Gangemi on Ontology Evaluation. As I consider making this the theme of my PhD-thesis - well, I am almost decided on that - I was really looking forward to his talk. Although it was partially hard to follow, because he covered quite a broad approach to this topic, there have been numerous interesting ideas and a nice bibliography. Much to work on. I especially didn't yet see the structural measures he presented applied to the Semantic Web. Not knowing any literature on them, I am still afraid, that they actually fail Frank's requirements from yesterday: not just to be taken from graph theory, but rather to have the full implications of the Semantic Web paradigm been applied to them and thought through. Well, if no one did that yet, there's some obvious work left for me ;)

The hands-on-sessions today were quite stressy, but nevertheless interesting. First, we had to powerconstruct ontologies about different domains of traveling: little groups of four persons working on a flight agency ontology, a car rental service ontology and a hotel ontology. Afterwards, we had to integrate them. Each exercise had to be done in half a hour. We pretty much failed miserably in both, but we surely encountered many problems - which was the actual goal: in OWL DL you can't even concatenate strings. How much data intefration can you do then?

The second hands-on-session was on evaluationg three ontologies. It was quite interesting, although I really think that many of these things can happen automatically (I will work on this in the next two weeks, I hope). But the discussion afterwards was quite revealing, as it showed how differently people think about some quite fundamental issues, the importance they give to structural measures compared to the functional ones. Or, differently said: the question is, is a crappy ontology on a given domain better than a good ontology that doesn't cover your domain of interest? (The question sounds strange to you? To me as well, but well...)

Pitily I had to miss today's social special event, a football match between the students of the Summer School. Instead I had a very interesting chat with a colleague from the UPM, who came here for a talk, and who also wants to make her PhD in Ontology Evaluation, Mari Carmen Suárez de Figueroa. Interesting times are lying ahead.

SSSW Day 1

Today's invited speaker was Frank von Harmelen, co-editor of the OWL standard and author of the Semantic Web Primer. His talk was on fundamental research challenges generated by the Semantic Web (or: two dozen Ph.D. topics in a single talk). He had the idea after he was asked one day in the cafeteria "Hey Frank, whazzup in the Semantic Web?"

In the tradition of Immanuel Kant's four famous questions on philosophy, Frank posed the four big research challenges:

• Where does the metadata come from?
• Where do the ontologies come form?
• What to do with the many different ontologies?
• Where's the Web in the Semantic Web?

He derived many research questions that arise when you bring results from other fields (like databases, natural language, machine learning, information retrieval or knowledge engineering) to the Semantic Web and not just change the buzzwords, but take the implications that come along with the Semantic Web seriously.

Some more notes:

• What is the semantic equivalent to a 404? How should a reasoner handle the lack of referential integrity?
• Inference can be cheaper than lookup on the web.
• Today OWL lite would probably have become more like OWL DLP, but they didn't know better than

The other talks were given by Asun Gómez-Pérez on Ontological Engineering, and Sean Bechhofer on Knowledge Representation Languages for the SemWeb, pretty good stuff by the people who wrote the book. I just wonder if it was too fast for the people who didn't know about it already, and too repeting for the others, but well, that's always the problem with these kind of things.

The hands-on session later was interesting: we had to understand several OWL ontologies and explain certain inferences, and Natasha Noy helped us with the new Protégé 3.1. It was harder than I thought quite some times. And finally Aldo Gangemi was giving us some exercises with knowledge representation design patterns, based on DOLCE. This was hard stuff...

Wow, this was a lot of namedropping. The social programme (we were hiking today) around the summer school, and the talks with the peers are sometimes even more interesting than the actual summer school programme itself, but this probably won't be too interesting for most of you, and it's getting late as well, so I just call it a day.

Summer School for the Semantic Web, Day 0

Today arrived in Cercedilla, at the Semantic Web Summer School. I really was looking forward to these days, and now, flipping through the detailed programme I am even more excited. This will be a very intense week, I guess, where we learn a lot and have loads of fun.

I was surprised by the sheer number of students being here: 56 or 57 students have come to the summer school, from all over the world - met someone from Australia, from Pittsburgh, and many Europeans. Happily, I also met quite a number of people I already knew, and thus I know it will be a pleasureable week. But let's just do the math for a second: we have more than 50 accepted students at this summer school. There are at least three other summer schools with related fields, like the one in Ljubljana the week before, there's one in Edinburgh, and the ESSLLI. So, that's about 200 students. Even if we claim that every single PhD student is going to a summer school - which I don't think - that would mean we get 200 thesises every year! (Probably this number will be only reached in three years or so)

So, just looking at the sheer amount of people working on it - what's the expected impact?

Interesting times lie ahead.