DISQUS

Thinking Clearly: OWL 1.1

  • Dan Connolly · 4 years ago
    Have you looked at the W3C XG/incubator process? I'd like to think it's appealing to your sort of group.
  • Dan Connolly · 4 years ago
    I'm getting 404's on the overview and syntax docs.
  • Duncan Hull · 4 years ago
    Hi Bijan, I look forward to using OWL 1.1 when it arrives, the links to Peters overview and syntax are dead, do you know where they moved to? Duncan
  • danja · 4 years ago
    IANAL, so there may be perfectly obvious justifications for moving to OWL 1.1. But I am involved with development on the web, and it seems mighty strange to me that 1.1 is under discussion (even 1.2, 2.0) when there are - how many? - I'd guess not many more than 10 implementations of OWL 1.0 reasoners. What are the features people need? Where is the community drive in this direction? I'm not suggesting there's necessarily anything wrong with these developments, it's just hard to see what's right.
  • danja · 4 years ago
    PS. I've found the "Irresistible SROIQ" paper - anything else you'd recommend? (Ideally more clearly related to real-world issues with SHOIN).
  • bijan · 4 years ago
    The Syntax and Overview links are live now, they are also attached to the email Peter sent annoucing them. (I'll email all the queriers about them to let them know).

    Re: justification. Er...why must there be 10 reasoners before we add features? Features aren't driven by implementations, but by use cases, and these extentions were all requested by users at the workshop. So that's the community drive. Believe me, no implementor wants to do these features because, by and large, they are not theoretically interesting. We won't be writing all that many papers about these (that aren't systems paper). Actually, that was perfectly clear in my post, so I don't understand, Danny, why you don't get it :)

    Besides, once you have two, if you don't want to fragment the community, you have to coordinate. We *are* a small enough community that we can coordinate the way we are doing. What's wrong with that? One reason we didn't move to an incubator group (well, ok, they weren't quite ready yet) is that we *want* to be as light weight as possible and try to grow the market (and the state of the art). It's possible that not all the features we develop here will make it into a W3C specification. (Maybe they'll turn out to be bad ideas, though I think only punning might have problems.)

    ("Real" reasoners out there are Racer, Pellet, FaCT++, Cerebra engine, and KAON2...that I know of. 3 of these are commercially supported! All are under active development (well, KAON2 might see a hiatus, but I believe Boris intends to keep it going). This is indicative to me of a healthy market. That's up from 1 commercial one when OWL went to Rec and only 3 (Racer, Cerebra and the aging FaCT) when OWL started/went to last call/went to CR even, though Pellet might have been there by then in a preliminary form.)

    One other 1.1 task is to identify useful but tractable subsets of owl (e.g., the EL family, or DL Lite). I think this will spawn a new user community and several new implementations.
  • bijan · 4 years ago
    Re: utility. Two core features are simply obvious things that should have or almost are in OWL: Qualified cardinality restrictions and user defined datatypes. QCRs were in daml+oil and are hugely important to bioinformatics applications (e.g.,
    "In contrast, a limitation in the expressive power of OWL-DL did cause con-
    siderable problems: the lack of qualified number restrictions (also called qualified cardinality restrictions)." in "A little semantics goes a long way in Biology"). Similarly, there are tons of requests for real user defined datatypes. In either case, the details are less important than agreement between the implemntors.

    The rest of the SROIQ stuff seemed both useful and easy. Having limited "triagnle" property composition gives you some useful "rule like" axioms.

    Given the minorness and the nice "rounding out" there was no reason not to add them.
  • danja · 4 years ago
    Thanks Bijan.

    The bioinformatics case sounds reasonable, but I'm afraid a lot of the rest sounds like adding stuff because it's possible, because it looks good on paper. Stable specifications, a decent number of implementations, web-wide practical application of these technologies...shouldn't they come before version 1.1?

    I do think the number of implementations is a point of note, in that they are a way of exploring the territory - not necessarily the territory of the DL community, but of the web community at large. For that wider community, I'd have thought things like looking at tractable subsets would certainly be valuable, in contrast to presenting a moving target of this year's model and theory - "DL2010...An Existential Odyssey", if you get my drift.

    I guess my basic concern is whether more engineering will somehow lead to more deployment, bring the SW closer, or just make life that much more confusing for the vast majority of relatively non-expert application implementers. I wish I didn't sound so negative about what I'm sure is valuable work. But when I look at the Web now I don't see a clear requirement for qualified cardinality restrictions or whatever, rather an environment crying out for a clear route towards adding semantics of *any* sort.
  • bijan · 4 years ago
    I started replying point by point, but, eh, it's pointless. :)

    I don't see you've raised a remotely salient point: "web wide practical application" is not a pre-requisite for vendors to coordinate the support of their uses, which is what we did. There were over 60 people at the OWL Workshop and consensus was overwhelming for this course of action (there was one person I recall expressing some similar meta qualms about it, and he participated with verve in the selection of things to go into 1.1.) So, we have users...why shouldn't we support them? In contrast, you don't seem to be an OWL user...why should I worry about your qualms? You don't see a need for the expressiveness, a load of other people do.

    I find your dismissal of the number of implementations as indecent just silly. I don't know what else to say about that. There are three companies selling OWL reasoners and two open source implementations. All of these are independently developed.

    As for making it more confusing for non-expert application implementers...how so? If you are an ontology developer, learn the new features and use them if you need them. If you don't need them, don't use them. Really, this just seems to be a non sequitur.

    In case it isn't clear, I'm not remotely swayed by your qualms. So don't bother repeating them :) I have been somewhat swayed by worries that calling it "OWL 1.1" (or OWL 2.0) might slow adoption because it makes it seem like OWL isn't finished. That's one reason for not taking it to a standards body (yet). This is just users and implementors getting together...what's the harm?

    (I don't buy the slow adoption argument, though I don't have conclusive evidence either way. I've heard people argue that not adding stuff slows adoption because it makes OWL seem stagnant. I know it slows adoption by people who need more expressiveness.)

    (It would be interesting to shift it into an incubator group. I'm not sure it's the best idea. The other point is that we wanted this to be very lightweight and inexpensive, whereas a normal working group is very expensive. An incubator group might be as cheap as an Oasis TC, which would be reasonable.)
  • danja · 4 years ago
    Ok, maybe I'm wrong to be concerned about this, and I don't expect to sway you. Certainly when you hide the OWL 1.1/2.0 label the effort has a different complexion, and development in this area is undeniably a good thing. But I am an OWL user, and probably more to the point am an active web developer who believes the SW vision is a very good idea. With all due respect, the requirements of a self-selected group of existing OWL theoreticians and users may not reflect the requirements of the Semantic Web. Again I could be wrong, but there's a scent of fragmentation here, and that makes me nervous.
  • bijan · 4 years ago
    I think you are wrong. I think you shouldn't expect to sway me because your arguments are either unfounded or vague. Actually, they are pure FUD, which is why they torque me off :) We switched to the 1.1 label to mitigate fears, but really, if you are all bent out of shape by that label..pfft. I'm not against marketing but the semantic web has far graver marketing problems than this. Plus, a user driven, vendor supported effort is exactly the kind of things one would expect to see.

    I see while you don't mention it, you do drop the "not a decent number of implementations". What is the decent number, btw? Do you have ANY criteria to offer for when we can make moves? I mean, this isn't an immediate standardization effort. It's preliminary.

    I don't fear the label.

    As for your last three sentence, well, they are offensive. The "insight" of a self-selected active web developer who believes the SW vision is a very good idea may not reflect the requirements of the Semantic Web either. We tried to reach out to a broad community. Our process was, and continues to be, open. We intend to gather experience. We intend to submit a note to the W3C. We are working against fragmentation.

    The Semantic Web isn't a person or even an institution. It doesn't have requirements. Grr. What a BOGUS dialectical move. I spend a great deal of my time thinking about the Semantic Web, why would you think we wouldn't consider these things? Or are we just dumber than you? Where's your reality check?

    I notice too that you completely ignored the vendor support.

    Ok, I'm ticked and should stop. It's perfectly fine to have concerns. It's theoretically possible that the OWL 1.1 effort will kill the Semantic Web, the Web itself, and life as we know it. But I don't think so, and in the absent of more specific evidence, I think it's fair to put such worries aside.

    (Oh, if you want another driver, datatypes are definitely key. We will hit a roadblock in supporting Web Services policy languages without better numerics. Our reduction of WS-Policy to OWL has spurred more interest in OWL from the Web Services guys than anything else I know of.)
  • bijan · 4 years ago
    BTW, you are, of course, welcome to attend the next OWL Experiences and Directions workshop next year, which will, again, be colocated with ISWC. And feel free to join the mailing list. I think you will be more effective if you take a less generally naysaying attitude, and be more precise in your qualms and their basis, but, eh, up to you.
  • danja · 4 years ago
    I'm sorry Bijan, I didn't mean to tick you off. I do have concerns, but obviously haven't articulated them very well (not that they are particularly well-formed - I think it was only last night I heard of OWL 1.1). That is all. If there is (or will be) wide support for this effort then my concerns are void. Either well, time will tell. I am interested in the tech/theory, so would very much like to join the mailing list, and I'll do my utmost to refrain from naysaying ;-)
  • bijan · 4 years ago
    Fair enough. There are risks, but I think the risks are greater in inaction in this matter. I'm certainly open to my being wrong wrong wrong, though I tend not to predict it.

    Currently there's a debate on the list about whether a more "modular" OWL 1.1 spec is a good idea...again it's all marketing. I personally (as you can see) think it's a terrible idea. I've gotten pretty grumpy about it, but hey, I'm a grumpy guy.

    I think catering to the bioinformatics folks is a v. good thing. Having OBO in OWL is a great tractor app, and if we can attribute a drug discovery or two to OWL ontologies...well, that's a great selling point.
  • Michel Bohms · 3 years ago
    I am applying OWL to product modelling. Decomposition is crucial here. Best practice pattern using someValuesFrom is unsufficient (not enough cardinality control). We clearly need QCR's. I have no problem having an OWL update if only it gives me standard way of doing QCR's. Second need is numeric ranges. Again. OWL1.1 would really keep me from going (back) to other formalisms (liek ISO STEP EXPRESS etc.). Finally it would be great to have some syntactic sugar for things like allowed values; current list constructs are very awkward. Can't wait till systems like protege and TBC are implementing QCR's/numeric ranges exactly as agreed by OWL1.1.