The Tetherless World Weblog

From Talis: “Jim Hendler at the INSEMTIVE 2008 Workshop”

“that people will (and do) create metadata when there are obvious and immediate benefits in them doing so. No-one really consciously sits down to share or create metadata: they sit down to do a specific task and metadata drops out as a side-effect.”

I can not agree any more. I have tried to tag all my blogs once upon a time, after a few weeks, I found myself bored because there is no clear, immediate benefits for doing so. I would only tag things that I have to, like to tell my friends a list of posts of the same topic.

The only tagging system that is consistently successful upon me is the gmail labeling: I organize mails related to the same task (like writing a paper) on daily bases, because it is very useful, and immediately useful. Even though, I only label a tiny fragment of all my emails.

I have seen too many people have their desktop full of files and too lazy to organize them – myself is one of them. Every year I have to spare a day or two to reorganize my harddisk, and dig out the hidden treasures of my “Downloads” folder. I believe for semantic web to be successful, creating an ontology should be at least as easy as and as useful as organizing files on a harddisk.

In fact, people are creating meta data or even ontology everyday: every email sorting, every contact on the cell phone, every folder creating, every calender item, every wiki post, … We just need to make them explicit, and most of all, without bothering the user to click even one more button.

Jie Bao

Stefan Decker raised a case “missing children” indicating that Description Logic, or more precisely open world assumption, maybe overkill because it is not needed in most real world applications even though AI researchers like it.

Michel Dumontier, as a researcher trying to adopt OWL, reviews the well-known semantic web benefits, again, from the SW developer community who hopes these nice features will be helpful to real world Web developers and users.

Tim Finin, “maybe we’re a victim of our own success”. Moving towards KR monoculture could be quite dangerous. He raises some examples that OWL does not fit, e.g. when encoding knowledge extracted from knowledge, a lot of information lots such as time, uncertainty, and provenance.

Ian Horrocks claims that OWL has good connection with other KR approaches, OWL is not going to solve all problems, but it is useful in general.

One biggest argument raised by many is that “is OWL useful?” not even “is OWL2 useful”. Of course there are both supportive and negative evidences, and neither side can convince the other side. Someone also argue that the learning curve of OWL will just stop potential user. (Industrial adoption is a better benchmark because researchers are more flexible).

Another issue is “scalability”. Jim Hendler tried to be even worse than Stefan, Twine is claimed to Semantic Web applications, it use a few pieces of OWL to scale up. In general, scalability is the non-negotiable requirement of Web data computation. That is database community avoids, for instance, recursion in relation algebra.

A third question, raised by David Karger, “what are we doing with OWL? Which pieces of OWL are actually being used, and Why?” (This is actually a motivation for OWL2, and why three OWL2 fragments are proposed. We are looking forward to see if OWL working group can give industrial users a good answer.)

Well, a fourth question is “OWL2 is KR, i.e. a family of Description Logics profiles that link to other KR languages?” and/or “OWL2 is trying to promote better web or semantic web applications?”.

Closing remarks (I did my best to keep it original)
* Ian, “choose hope, not fear”
* Tim, “I can see Russia from my house”
* Michel, “OWL is pretty good language”
* Stefan, “if you did not fix the little thing, you may miss the boat”

By Li Ding
Greetings from ISWC 2008