Ivan’s private site

October 15, 2008

Semantic Web and uncertainty

The issue of uncertainty on the Semantic Web has been around for a while now, although it is still largely a research issue (Though not only; C&P has an extension of their Pellet tool to handle a particular probabilistic extension of OWL; but I am not aware of any other commercial system of the kind.) Ken and Kathryn Laskey and Paulo Costa have been organizing a series of workshops (the URSW series) on the subject for several years now (there will be one on the coming ISWC2008 conference, too!), and there was also a W3C Incubator Group on the subject that issued a report not a long time ago. But still a lot to be done…

The reason I remembered all that is because I found a survey of Thomas Lukasiewicz and Umberto Straccia[1] that is worth reading if you are interested in the subject. The survey gives a separate description of probabilistic, possibilistic, and fuzzy extensions of the DL dialect that is at the basis of OWL DL, together with further references if one wants to dig deeper (156 of those!). It is not an easy read at all, and I couldn’t say I understood all the details described there, far from it… But as all good surveys do it gives you an idea or, or refreshes your memory on what is happening in the area. And that is always incredibly useful.

The approaches described in the paper are fairly high level in the sense that (as the authors emphasize, too) the extensions are all on top of SHOIN(D), ie, OWL DL. That makes the constructions sometimes quite complex (mainly in the probabilistic case) and they are probably difficult to use for a lambda user. (Although, who knows. They are certainly complex to implement, but maybe the usage is not that bad. I am not sure.) However, the authors themselves refer to alternative approaches on top of simpler DL dialects (without giving too much details). It would be nice to have a survey on the extensions of a level corresponding to simpler OWL profiles like OWL RL that the OWL WG at W3C is also working on now. Just as OWL RL might be a good “entry point” for a large family of users into the world of OWL, an uncertainty extension of that level might be of a great interest, too…

Reading this survey also reminded me of short paper by Fensel and van Harmelen[2], “Unifying Reasoning and Search to Web Scale”, on which I had a very short blog a while ago. I just wonder whether fuzzy or probabilistic reasoning may not be a good approach to the problems they describe there… Althought this is clearly still a long way off.

Anyway. I learned something today…

  1. Lukasiewicz, Thomas, and Umberto Straccia. “Managing uncertainty and vagueness in description logics for the Semantic Web.” Journal of Web Semantics: Science, Services and Agents on the World Wide Web 6, no. 4 (2008). Available on line as a pre-print.
  2. “Unifying Reasoning and Search to Web Scale”, by Dieter Fensel and Frank van Harmelen, IEEE Internet Computing, Volume 11, No. 2, March/April 2007.
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1 Comment

  1. […] reason I remembered all that is because I found a survey of Thomas Lukasiewicz and Umberto Straccia[1] that is worth reading if you are interested in the subject. The survey gives a separate description […]

    Pingback by Semantic Web » Blog Archive » » Semantic Web and uncertainty — November 28, 2008 @ 5:20


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