Valentin's Blog

One of the main activities in CKC 2007 is an open challenge to evaluate a number of tools for collaborative constructions of knowledge. The aim of the challenge is to test existing approaches to figure out collectively what we expect of such tools, which features are useful and which are not, and which direction the field should follow. 

Please go to:
http://km.aifb.uni-karlsruhe.de/ws/ckc2007/challenge.html

For example you can try out collaborative Protégé or our SOBOLEO tool I described earlier.

Labels: SOBOLEO

With the growing interest in rule languages in the Semantic Web and the Business Rule community it is time to look again at the issue of debugging rule bases. New challenges have arisen since the time most concepts for today's debuggers where created: end user programming has grown in importance, graphical editors have become more common and programs are increasingly interconnected. Today there is no debugger for rule-based systems that takes into account the declarative nature of rules and that addresses these challenges.

This paper proposes Explorative Debugging as a paradigm for building debuggers that truly take into account the declarative nature of rules. The Inference Explorer is presented as an implementation of the explorative debugging ideas.

A publication by me and Andreas Abecker that was accepted for this years SEKE conference (Nineteenth International Conference on Software Engineering and Knowledge Engineering). 

It is a paper more about the challenges for debugging and less about the solution ... I hopefully post a paper that concentrates on the core concepts of Explorative Debugging in a week or two (IF it gets accepted :)

The entire paper is here.

Labels: KBSDevelopment, publication

Furthermore the authors are not aware of any proof that completely representing a domain is a cost efficient solution to any business problem.

Just a sentence I wrote in a publication I work on. Re-reading it I realized that this is actually a shocking statement - does this mean that all old fashioned attempts to build ontologies are wasteful? Or is there this proof but I just don't know it?

Actually I think that this only applies to really old fashioned attempts to build an ontologie - those that actually somehow strive for completeness in representing a domain and lose track of the task an ontologies is supposed to be used for. In general this kind of thought is just another reminder that the "an ontology is a formal conceptualization of a domain" definition is incomplete - any actual ontology is an artifact created for some purpose. Forget that and you'll never finish modeling and end up with something that you can neither verify nor validate.

Labels: SemanticWeb

There was an annonyingly inprecise piece over at ReadWrite Web about Google as "The Ultimate Money Making Machine" .. but thinking about it brought me to two conclusions:

1) If you look at what really matters - money - then Google is first and foremost an advertisment brokering company. By "Our goal is to organize the worlds information" Google actually means: "Our goal is to place ads next to the worlds information" ;)

2) Hence any challenger to Google will most likely not be a better search engine but a better ad broker. And if I can speculate a bit more: this challenger will not succeed by challenging Google on "traditional" AdSense like adds, but by brokering ads in games, virtual worlds, to mobile phones (based on location), internet video .. or by better integrating old ad channels like print, tv ads, product placement ....

Of course, Google knows that - thats why they bought YouTube and a company that specializes in in-game advertisment; that's why they experiment with TV-ads and ads in print. But unlike with "traditional web ads" they don't dominate the market in this areas (yet) and hence there's a much better chance for competitors.

But well, all this brings us back to the question of Semantic Web Advertisments ;)

Labels: SemanticWeb, Web

Ask.com, Google, Microsoft and Yahoo! have announced support for a new feature of the Sitemap standard - you can now link these XML files (that describe a sites structure) from the robots.txt file and don't need to manually alert every search engine to where your file is. This reminded me of the "Why the Semantic Web will fail" debate a few weeks back - remember the blog post that claimed that, I quote: "The Semantic Web will never work because it depends on businesses working together, on them cooperating". This new cooperation over the Sitemap standard is just another example of how competing businesses are cooperating, even creating metadata standards.

Revisiting this blog, however, I found that its author, Stephen Downes,  has actually addressed my critic (among others) in a second blog post. I had said:

RSS, ATOM and iCal are examples for data standards jointly supported by different companies - there's just no reason to assume that this list cannot grow.

And he replies:

Neither RSS not Atom are RDF (except for RSS 1.0, which has a usage of about 3 percent). I also posted figures on my website just this week showing that iCal usage is something like 7 percent. iCal isn't RDF either - hence the need for a converter http://torrez.us/ics2rdf/ and the resulting proliferation of RDF versions of iCal, none of them official. Meanwhile, neither Google nor Outlook are based in iCal.

Which I don't accept as a rebuttal of my argument. He said: "can't work, businesses don't cooperate, don't come up with joint standards", I said: "they do, look at these standards", he says: "that's not RDF" - but that's not the issue.  I personally don't see the vision of the Semantic Web as restricted to "only RDF", I'm fine with Semantic Web applications build with XML/RSS/ATOM. For me RSS is conceptually a pure breed Semantic Web application - whether  it's build on RDF or not. And even if I where to grant the point that these companies have yet to agree on a "real" Semantic Web standard, he then has to argue that "business do cooperate but they would never do it on Semantic Web standards" .. for which I don't see any arguments right now.

And about iCal and Outlook/Google: Well, the Outlook I use also displays the data from my Google Calendars - and the integration is done with iCal. Neither of these applications may be "based in iCal" - but they surely support it.

Sadly he didn't post a link to this analysis that lead to the "iCal usage is something like 7%" statement and I couldn't find it - so I'll probably never know the answer to the "7% of what?" question (of all Internet traffic? applications aggregating calendar data?)  ;)

Labels: SemanticWeb

The good old Semantic Web layer cake ... it has served us quite well by giving some illustration to the un-illustrateable. But surprisingly there seem to be people that actually take it literally and thereby it is starting to cause more harm than good - for this reason it should be retired, never to be shown again.

Here it is, in all its glory and the most current version I could find (from Jim Hendlers "Dark Side" slides).

So, how can this innocent looking boxes hurt? Let me enumerate a couple of ways:

• The layer cake gave us unreadable serializations. The ugly RDF/XML was only the start, to be followed by the even worse serialization of OWL in RDF in XML - that even hints at a RDF-OWL compatibility that isn't there.  We have to stop this before someone comes up with a serialization of Prolog in RIF in RDF in XML!
• The idea that "Trust" is the final and last stage* to be added on top lead to the ignorance in the SW community of trust issues - even though this is one of the most important questions for the future web. 
• The idea that we first have to build this entire "protocol stack" before real Semantic Web applications can be build was one of the reasons the Semantic Web community became so academic and self-centered.  
• The layer cake makes it hard to bring the lowercase semantic web developments into the SW mainstream, this would require the SW community to accept that in fact you can have meaningful and helpful semantic web applications just on top of the two lowest layers.
• Finally the layer cake facilitated the hijacking of Semantic Web research by the old fashioned logic and knowledge representation communities/ideas (which in turn lead to formalisms that for all we know are too slow and too brittle to work on a web scale). 

*: This "UI" layer is relatively recent, trust used to be the uppermost layer for most of the time.

Labels: SemanticWeb

Google Video has a talk about Yahoo Pipes. In general its a nice and gentle introduction to pipes, I found four tidbits of information mainly about the future plans of Pipes very interesting:

• In the new future they plan to allow you to add your own webservices as modules. 
• They are looking into ways to allow you to safely build Pipes on your private, password protected data (such as emails, calendars etc). Although it sounded like this is still quite a bit off.
• Yahoo Pipes is internally build on top of XML; its agnostic to whether its RSS or XML/RDF.  In the beginning they put the focus on RSS to make the tools easier to understand.  Not sure whether this is good news - processing RDF as XML really is neither easy nor powerful (compared to processing it as RDF).
• In general they struggle with the Power vs. Simplicity tradeoff; for example that led them to postpone the release of a database like "join" module for XML files.

Sadly they did not speak about the business case behind Yahoo Pipes, how Yahoo plans to earn money with this service.

Labels: Mashup, SemanticWeb, Web