Stefan Decker on the Semantic Web

The W3C Semantically-Interlinked Online Communities (SIOC) Ontology Submission has been acknowledged. My greatest hope with the submission is that the specification will show to people what the semantic web is and it not - that it is not some magic, but something grounded, simple and easily deployable which can lead to new ways how data on the web can be used and interconnected - e.g., with the SIOC Explorer. And of course there are commercial opportunities opening up as well, since the SIOC adoption is developing nicely. Thanks to John and Uldis and all the other contributors for the hard work they have put it!

I recently found the article 'Is Web 2.0 The Global SOA?' which creates a linkage between SOA (Service Oriented Architecture) and Web 2.0. The article readily admits that "both Web 2.0 and SOA are already slippery, nebulous concepts", but that nevertheless there are "unmistakable patterns within each that actually are very tightly related, though wrapped in slightly different cloth".

The article does a good job in identifying the common aspects and the differences. Coming from a business perspective, both conceptsdeal withbest practices for building business processes into vast supply chains. In contrast toWeb 2.0, SOA has the concept of orchestration - (although mash-ups in Web 2.0 are coming close).

On the other hand, "Web 2.0 embraces people, collaboration, architectures of participation, social mechanisms, folksonomies, real-time feedback, etc. All things that SOA, in its grey, dull, corporate clothes, does not, at least not explicitly."

The article concludes with "Yes, so Web 2.0 is a global SOA, done right for the whole world. It's big, it's everywhere, and it's here today."

A similar article notices a dysfunctional gap between SOA and Web 2.0. This gap can be bridged by making the semantics of it's parts more explicicit, allowing the different parts to interoperate (and also making both concepts less nebulous and slippery). There are currently several efforts to add semantics for SOA and Web 2.0. Efforts like WSMO(Web Services Modeling Ontology)are aiming atadding semantics to SOA, whereas efforts like SIOC (Semantically-Interlinked Online Communities) are adding semantics to Web 2.0.

It will be interesting to watch how the different efforts converge - my expectation is that Semantic Web 2.0 gets more service oriented, whereas the semantic SOA need to get more consumer oriented and lightweight in order to facilitate such a convergence.

It is an interesting space to participate...

I just got the notification that our tutorial proposal (together with John Breslin) for the World Wide Web Conference 2006 on "Semantic Web 2.0: Creating Social Semantic Information Spaces" has been accepted. The contents of the tutorial will be about Semantic Blogging, Semantic Wikis, Social Semantic Collaborative Filtering and other new approaches related to applying and deploying semantics andsocial networks for information dissemination and assessment. We will introduce the audience in the state of the art in this area, including the approaches that are developed in the Semantic Web cluster at the Digital Enterprise Research Institute. The tutorial is scheduled for Friday, May 26, 2006 in Edinburgh, at the WWW Conference.

SNARF, the Social Network and Relationship Finder, developed by Microsoft Research, deploys social network information for organizing information, helping users to organize their email in Outlook. A quote: The coolest thing to me, Brush says, is the power of collecting and presenting simple information. I was surprised and pleased by how much power you can get from simply counting the e-mails you send to people and using that information to organize e-mail for users. Social information is very powerful. It looks like we are on the right track with NEPOMUK and the Social Semantic Desktop: social networking information is relevant for assessing all information that we get and also send - not only email, but instant messaging, documents, websites, VOIP callsetc. Developing open standards is the challenge in front of of us. FOAF is a beginning, but we need far more: standards and protocols for dissemination of information and documents within social networks, ranking of information etc. Develping these standards is an important aspect of the NEPOMUK project.

The PODS/SIGMOD/VLDB database community is developing interest in the Semantic Web. Enrico Franconiwill give an invited tutorial on the Semantic Web at the PODS 2006 conference.Alsothe article "From Databases to Dataspaces: A New Abstraction for Information Management" by Michael Franklin, Alon Halevy and David Maier (Sigmod Record, Dec. 2005) contains the following quote in section 5.1 (Relationships to Other Field): "Recent developments in the field of knowledge representation (and the Semantic Web) offer two main benefits as we try to make sense of heterogeneous collections of data in a dataspace: simple but useful formalisms for representing ontologies, and the concept of URI (uniform resource identifiers) as a mechanism for referring to global constants on which there exists some agreement among multiple data providers."

It is nice that these developments are acknowledged in the database community. However, the database community is very heavily invested in the XML stack, and this paper is no exception. So I am curious how the database community is planning to integrate ontologies and URIs into the XML stack and at the same time get global consensus on that integration - when there is already an alternative stack (based on RDF) building on URIs and ontologies. Interestingly enough, query processing and data management questions relating to the RDF stack are so far ignored by the database community (with a few notableexceptions). This leads to the fact that data management solutions including query languages for RDFare mostly developed inside the Semantic Web community without much involvement from database people. But maybe this will change now.

In that respect it is also insightful to read the transcripts of the The Lowell Database Research Self-Assessment Meeting, May 2003, of which conclusions have been recently published in the Communications of the ACM, since it shows the understanding that senior database researchers have of their field in relation to the Semantic Web. Here are some extracts:

• Bruce Croft - IR & structured data.
  semantic web - "if you made the web a database" - this is make the web into a knowledge base and that won't happen - we've had a debate for decades about manual vs. automatic representations of what documents "mean" and both work better than either one but creating the manual versions is very hard. That's the lesson from the IR work
  go for knowledge or statistics?
• Ullman - Re semantic web - you talk about semantics but when you have to do something you do syntax. If you take the temperature in Lowell thing you ought to be able just to say "temperature Lowell" - How much more is there to do? Crawlers are bad at this because it is timely. History in Lowell would work better on Google. Im curious as to what you think is the advantage of focusing on deep understanding rather than giving people tools to use?
• Widom - When did you add semantic web? I'm not responsible for that.
• Abiteboul - All this is syntax. Makes Ulman happy; the most fundamental difference from relational DB to web is that you don't know the semantics.

These statments indicate to me that senior database researcher are mostly not interested in the Semantic Web. However, the final report then has the following paragraph (in section 3.11: New User Interfaces):

"Perhaps most interesting is the research opportunities suggested by the term semantic Web. While it may be unclear what the concept truly entails, much of the recent work has centered on ontologies. An ontology characterizes a field or domain of discourse by identifying concepts and relationships between them, usually in a formal language. We mentioned in Section 2.2 how this work may support information integration, since a fundamental problem in that area is the inability to combine databases that at a deep level are talking about the same thing, but do so in different terminology. Work on ontologies may likewise enable users of databases and other resources to use speech or natural language to query in their own terminology. The database community should be looking for opportunities to exploit these developments in future database management systems."

This paragraph indicates some interest - although this section does not acknowledge that the Semantic Web is build on the RDF stack of technologies and it rather sees the result of the Semantic Web as only relevant for user interfaces.

I just noticed the article from Dan Zambonini "Is Web 2.0 killing the Semantic Web? ". From my perspective the article shows a misconception that people seems to have around the Semantic Web: the Semantic Web effort itself does not provide applications (like the Web 2.0 meme indicates) - it rather provides standards to interlink applications. So for Web 2.0 (or the Semantic Web 2.0) Semantic Web recommendations provide a way to interlink applications. Within DERI we are actually building examples - these include the SIOC specification to semantically interlink community sites, a Semantic Blog, the Social Semantic Desktop, and more. The most interesting part is that the step from a Web 2.0 application to a Semantic Web 2.0 is a small step, but it creates lots of tangible benefits. For a better explanation see the previous blog entry.

UPDATE (October 24, 2005): I just got notified that the panel was canceled since the conference organizers felt there was too much semantics involved. Oh well...

I just accepted an inivitation for a panel at the 3rd International Conference on Service Oriented Computing (ICSOC), Amsterdam, The Netherlands, December 12-15, 2005. The titel of the panel is "Semantic Web and Semantic Web services: Can One Go without the Other?". The other panelists are Amit Sheth, John Domingue, Frank Leymann, and Martin Hepp. As a Semantic Web scientist this is an irresistible opportunity to get grilled within the European context, which is very heavily invested in Semantic Web services.

Without a doubt Semantic Web Services have their application area, but in the first place the Web is a communication and collaboration medium between humans - and this potential has not been fully exploited so far. This slidedescribes the idea and the path forward looking at the social semantic side of the Web.

The Shanghai Jiaotong University has published their yearly Academic Ranking of World Universities for 2005. Harvard University, University of Cambridge and Stanford University fill the first ranks - probably as expected. The University of Southern California has reached rank 50.

Only three Irish Universities are in the first 500 - Trinity College (rank 236). University College Cork (rank 458), and University College Dublin (459). My current employer, the National University of Ireland, Galway does not make the first 500 places (whereas Stanford, USC, and Karlsruhe do). The reason is not very hard to find - the ranking ist mostly based on research results and reputation, and NUIG has only started the transition into a research university.

However, the level of funding and activity inside NUIG is increasing - examples include the centers DERI and REMEDI, Alan Ryders'group or theNational High-End Computing Centre, directed by Andy Shearer(all of them funded by Science Foundation Ireland),which increases the pressure on NUIG to transform itself into a service-oriented research university. The transformation naturally puts a lot of stress on the system and it is not without pain on every side. But the university is changing and more and more emphasis is given to research excellence.

To quote Iarnrd ireann's (Irish Rail) advertising slogan: "We're not there yet, but we're getting there."

The availability of VOIP implementations based on standards (like Asterik or even Java-based implementations will enable the integration of VOIP wither other applications. A paper by Tomas Vitvar discusses the integration of VOIP with Semantic Web Services. Also an interesting application will be the integration of VOIP with the Semantic Desktop. Consider a scenario where a user gets a call from a project collaborator. As soon as the call arrives metadata is extracted from the call (either implicit metadata (e.g., the callee) or explicit metadata (e.g., the project the call is related to) and relevant project information is openend and presented automatically, which establishes the context of the VOIP call. Part of this scenario can be realized without any changes to the SIP - other parts (e.g, the transmission of explicit metadata) may require protocol enhancements.