Live from ISWC 2008 in Karlsruhe

It is already the last day of ISWC’08, which had some really good papers, comments from the attendees during the sessions, and ample ambience for networking. I will discuss the keynote speeches first, then mention a few research papers, and close with a few general remarks.

Ramesh Jain gave a good keynote speech on semantic multimedia searches—or: the lack thereof and how to bridge the semantic gap between mere images and the meaning we attribute to them so that we can find the right multimedia in the sea of images, video, etc., perhaps by what he denoted as the “Event Web” as multimedia items are ‘snapshots’ of larger events that give context, and meaning, to those multimedia items. In addition to the extant ontologies, such as LSCOM, he is developing an ontology for events so as to better annotate the items and, consequently, obtain better search results. John Giannandrea’s keynote on Freebase on the other hand, can indeed be summarized by the quote from Babbage he gave: “errors using inadequate data are much less than those using no data at all”. While obviously the wisdom of the crowds and domain expert input for building knowledge bases is a laudable idea and has achieved remarkable successes toward the proverbial “80%”—but it is the remaining “20%” that is the hard part to take it from a ‘web 2’ version to a `web 3’ version of semantic searches (cf. string matching) to retrieve the right set of answers instead of a sea of links, software agent collaboration to plan your trip based on your requirements, and so forth. To take an entertaining example from another knowledge base, SNOMED CT, which is adopted in several countries: while Stefan Schulz and I were searching for suspended concepts and relations (suspended sensu [1]), we came across a congenital absence of one tooth that is a subtype (is a in SNOMED CT) of congenital absence of mouth, of jaw, and of alimentary tract… never mind that acquired absence is a body structure, and the concoction of previous known suicide attempt that throws together temporal, epistemic, and intentional notions into one concept.
The third keynote speech was by Stefan Decker from DERI, and rather provokingly about “how to save the Semantic Web?”. Based on an analysis of the successes of physics, he identified five points: (i) appealing unified message, (ii) credibility, (iii) concerted lobbying efforts, (iv) potentially transformational power, and (v) doable agenda for successes. His answers for AI in general and Semantic Web in particular are, respectively: yes-?-yes-yes-no and no-?-yes-yes-yes. In addition, his vision for the Semantic Web is to aim for a network of knowledge and collaborative problem solving and recollecting that the Semantic Web is, ultimately, for humans. However, part of the latter point was that he dismissed (well, ridiculed in a not so entertaining way) the required theoretical foundations, which annoyed quite a few people in the audience. During the break afterwards, one put forward that it is precisely because of theoretical foundations that physics continues to do well. After all, building tools on quicksand—compared to fundaments on solid ground—is not sustainable in the long run. Surely, the human and engineering components should, will, and gradually already are receiving more attention as the topics of the papers attest, be it here or ESWC and emerging workshops about them; e.g. there was a session on user interfaces and one semantic social networks. On the other hand, is the “semantic desktop” that Decker proposes really a sexy “appealing unified message”? Surely we can—and do—do more, be it to, from a end-user perspective, facilitate bioscientists in their research or focus on goals to streamline public administration and open up and enhance e-learning, to name just three sub-areas.

Of the presented papers, several were more detailed or improved versions of earlier works, such as the one about testing with probabilistic reasoner pronto using P-mathcal{SHIQ}(D) (see here), approximating RCC in OWL [4] and details about how IBM managed to have the SHER scalable reasoner for expressive ontologies (represented in the mathcal{SHIN} DL language) SHER [3] of which earlier work had been presented or discussed during OWLED’07 and this year’s introduction of Anatomylens as real application. SHER achieves scalability via summarization of the ABox and filtering. The RCC & OWL paper [4] seeks to solve the problem of performing spatio-thematic queries by approximating RCC8 (the full-blown version cannot be fully represented in OWL) and use that for consistency checking w.r.t. assertions in the ABox.

Putting data types in an ontology is from a formal ontology (and, eventually database and ontology interoperation) perspective problematic, but many developers seem to want to have them (treating an ontology as if it were a formal conceptual data model) and better than currently possible in OWL. For those who want more of it: your requests have been heard, and with data types in OWL 2, you will be able to state, e.g. geq_5 land leq_{10} , name data ranges, it redefines XSD numeric data types, rdf:text is added as well as date/time, and there will be a data type checker [6].
A nice feature that even I have used during development of the ADOLENA ontology, are the semantic explanations for the deductions (originally in SWOOP, and later also in, e.g., in Protégé 4 where after classifying, one clicks on the “?” that appears with the inconsistent and inferred classes). More precisely, Matthew Horridge presented the work on laconic and precise justifications [2], which has been nominated for the best paper award. Their work enhances the way how explanations are computed and what information about it the justifications is needed so as to give only the minimal required information for repair; put differently: toward minimizing the haystack where to find the needle to fix your ontology.

Several presentations are, or will be, made available on Video lectures.

Last, some indication of where the semantic web still has to go to, just a tiny practical example: the conference site called for tagging blog posts with iswc2008 or ISWC 2008, and if you click their link to do a Google blog search you are supposed to get a long list. But it does not. In fact, their defined Google blog search searches on iswc2008 or “iswc 2008” that does not work when I had it in the text of two posts—well, I had used ISWC’08 and that particular permutation of semantically the same thing was not in the pre-defined search term. Even after changing it on 28-10-2008, it still has not been recognized. A non-blog web search does return lots of hits. Not that I want to insist having my two-seconds fame on the ISWC website as one of the results, but something like that simply should work by now, or ought to… I will add both their desired tags this time, and let’s see what happens. UPDATE: the tagging worked, so there are just few bloggers who bother with the manual tagging, it seems…

Overall, it was an entertaining and very interesting conference, with—from a research perspective—both encouraging results and plenty of topics for further research.

[1] Artale, A., Guarino, N., and Keet, C.M. Formalising temporal constraints on part-whole relations. 11th International Conference on Principles of Knowledge Representation and Reasoning (KR’08). Gerhard Brewka, Jerome Lang (Eds.) AAAI Press. Sydney, Australia, September 16-19, 2008.
[2] M. Horridge, B. Parsia, U. Sattler. Laconic and Precise Justifications in OWL. Proc. Of ISWC’08, 28-30 Oct. 2008, Karlsruhe, Germany.
[3] Julian Dolby, Achille Fokoue, Aditya Kalyanpur, Li Ma, Edith Schonberg, Kavitha Srinivas, and Xingzhi Sun. Scalable Conjunctive Query Evaluation Over Large and Expressive Knowledge Bases. Proc. Of ISWC’08, 28-30 Oct. 2008, Karlsruhe, Germany.
[4] Rolf Grütter, Thomas Scharrenbach, and Bettina Bauer-Messmer. Improving an RCC-Derived Geospatial Approximation by OWL Axioms.
[5] Boris Motik and Ian Horrocks. OWL datatypes: design and implementation. Proc. Of ISWC’08, 28-30 Oct. 2008, Karlsruhe, Germany.


10 responses to “Live from ISWC 2008 in Karlsruhe

  1. About the tagging, you could use faviki granted there is a ISWC08 entry in Wikipedia, which I suspect there isn’t. 🙂

  2. your suspicion is correct…
    I just re-checked the search results from the ISWC’08 website, and limiting it to last month’s posts, it still only finds 8, even though there are more people blogging about the conference (e.g., here, here [he tagged with “ISWC”, a ‘wrong’ tag…] and here). A niftier tagging system other than manually and by-chance could help. Any programmer-volunteer for that to have it running for next year’s ISWC? With as goal to beat this year’s stats, it will be easy… 🙂

  3. Hi,

    I just found your blog and I am a bit surprised about them:
    You wrote: “However, part of the latter point was that he dismissed (well, ridiculed in a not so entertaining way) the required theoretical foundations, which annoyed quite a few people in the audience.”. Not was not my intention.
    In fact I am a logician and AI person (by education) myself and I am always for good theoretical foundations, so if that was what I communicated I did something wrong.
    But I am curious: what exactly caused you to pick that up?
    Also I did not get a lot of feedback about annoying people (provoking yes, that was in fact my intention). But where did get people annoyed?
    (The talk is online on videolectures btw).



  4. Dear Stefan,

    The joke–assuming that was what it was–about all the formalisms and setting them aside did not come across that way: directly after the presentation during the break, at least the about 10 theory-focussed attendees I had coffee with, had taken it as an insult, as if the formal foundations would not be necessary, or, at best, to be avoided or ignored, i.e., as if their life’s work could be trivialised away. Annoyed would be an euphemism to characterise their mood, and perhaps that contributed to it that they did not go into a discussion with you.

    As for myself, I’ve heard comments and debates about logic vs the more user-oriented approaches several times before, so I was not surprised. Concerning the “not so entertaining way”, I found, e.g., Jeremy Rogers’ take on that issue, including the “ontology inquisition”, and likewise for the presentation by Robert Stevens, better worded and more open to discussion (slides downloadable here, but they had the smaller venue in their favour as well, being the WG6 Workshop on Ontology and Biomedical Informatics, Rome 29 April – 2 May 2005).

    Thinking back to your keynote, the intended message may have been more effective without the “anti-logic-intro”, which, clearly from your blog comment, did not add anything substantial to the analysis and vision your were putting forward anyway, but it instead contributed to impressions of either-or instead of both-and.

    best regards,

  5. Marijke,

    please point out to me where in the keynote I did what your are accusing me to do.
    As I said, the lecture is available on videolectures.
    ( )
    Also my talk was not about Logic vs a user oriented approach.

    The intro (I assume that was the reason for your comment) was a response to Tim Finin’s (the conference chair) announcement (at the conference dinner) that I would be talking about 2nd order logic and would save the Semantic Web with 2nd Order Logic (his statement). I decided to use his announcement (with was done without my knowledge) and indeed start the talk with a typical logic presentation. And indeed the slides are original slides.
    However, the real talk had nothing to do with logic.
    I am not sure where you got that from.

    If people were annoyed – maybe the I hit a nerve?
    If that was the case – even not intentionally – then the talk was probably not that bad 😉
    Or could it be that people heard what they wanted to hear?



  6. Marijke,

    I posted the comment below on the videolectures site.
    ( )
    I hope that clarifies the issue.

    Best regards,


    Dear visitor,

    the introduction of the talk needs an explanation to be understandable.

    The intro was a response to Tim Finin’s (the conference chair) announcement (at the conference dinner the night before) that I would be talking about 2nd Order Logic and would save the Semantic Web with 2nd Order Logic (his statement). I decided to use his announcement (with was done without my knowledge) and indeed start the with a couple of slides on 2nd Order Logic – to set a contra point to the rest of the talk.

    Some people misunderstood the introduction as me demoting logic as a foundation for the Semantic Web. That was not my intention – I myself have a background in logic and some of my most cited papers are about logic and inference mechanisms for the Web.
    Indeed 2nd Order Monadic Logic has interesting properties for describing graphs and it may be worthwhile to investigate the relationship to RDF graphs (I have not done this).

    My talk was about how to communicate the Semantic Web ideas to a greater audience – and indeed logic may not be the most effective tool here.
    But of course logic (also 2nd Order Logic) are worthwhile areas of research also for the Semantic Web.

    I hope this comment clarifies some of the questions and remarks I got.

    Best regards,

    Stefan Decker

  7. >The intro (I assume that was the reason for your comment)

    yes. for the rest of the presentation, I duly had made notes and found it worthwhile to summarise the 5 points and analysis and include it in the blogpost. (If the semantic desktop is “the” answer to the analysis, is a separate point: the Semantic Web can be used for a variety of application areas)

    >However, the real talk had nothing to do with logic.

    true, and, in turn, it was not my intention with the post to say that the main or only message was about logic.

    I do not know if all complainers were at the conference dinner and had heard Finin’s speech. I was not, so I did not know that Finin had announced you would be proclaiming salvation with 2nd order logic. To me at least, this is a useful clarification to put it better into context. Thank you for having taken the time and effort to do so.

    Best regards,

    p.s.: regarding your last two questions in #5 and videolecture comment in #6: I’ll forward your responses and explanation to some of the logicians.

  8. Marijke,

    thanks for highlighting a possible missunderstanding!
    That been clarified, if this blog could be exported using the SIOC vocabulary
    (Semantically-Interlinked Online Communities)
    it would be part of an explicit network of conversations going on in the Semantic Web and other topics (and I would have seen this particular comment much earlier).
    Fortunately there is a easily installable plugin for WordPress available to export blog posts and conversations like the one above using the SIOC format, so this will not take a lof of effort (see ).

    Search Engines like Yahoo can then pick up the SIOC
    ( ) and make it available again. Arguments like the one we had can be made much more explicit and interlinked.

    And you may even agree with me that applications like these may finally show the potential of the Semantic Web to a general (Web) audience and indeed provide a crystalisation point fur further development 😉

    All the best,


  9. Dear Stefan,

    the idea with SIOC and interlinking is nice and probably useful too, but…. it appears that this blog, at present, cannot be exported using the SIOC vocabulary, because with the current implementations, I need to install a plugin and plugins can only be installed with a but not a blog (differences are listed at

    Given that wordpress periodically does add new features to its software for all its bloggers so as to link the contents better across various websites (over the past 2 years, features such as the tags and linkedin-linking), a feature request and lobbying for more Semantic Web extensions would be needed. I suppose this post with the comments could serve to illustrate some of the problems of not having it—there is a point for further development indeed 😉


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