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Re: Pellet gives strange, wrong error with Booleans

From: Stephen Larson <slarson@ucsd.edu>
Date: Thu, 30 Aug 2007 12:41:36 -0700
Message-ID: <94d6208f0708301241t68bdaa33nb0215514a8f0d637@mail.gmail.com>
To: "Bijan Parsia" <bparsia@cs.man.ac.uk>
Cc: "Owl Dev" <public-owl-dev@w3.org>
Bijan... I apologize.  I apparently have gotten on your bad side and I wish
to amend that.

All I wanted to do was bring to your attention an issue that I'm having
between Protege and Pellet.  I am probably not the only person in the
signficant Protege userbase who has run into this problem.  But I might be
the only one who has been able to articulate the problem well enough to
advise you of it.  I came into this from the mindset that it is in your
interest to increase your userbase, a lot of which comes from Protege, and
thus you would want to know about this, and that would lead you to want to
look into it.  Your position is that I am asking for you to fix my personal
issue, and therefore I have responsibility to tell you how to resolve the
issue.  I am sorry for giving you that impression.  I did not intend to
hijack your time.  I should have posted to the support list to begin with.
I would ask, though, that you consider the abstraction barrier between your
users' expertise and your own.  There are a lot of people who wish they
could use ontologies, but they can't because it isn't easy.  I sincerely do
think the community is better off when someone who knows what they are doing
takes responsibility for these interfaces and tries to make sure that
bridges between applications work.  All that I could see from my screen was
that Pellet was reporting the problem, so that's why I started there.

I see now from the other list that Protege wasn't implementing the DIG
protocol correctly and is looking to amend that going forward.  Great.  This
is the result of me cross-posting to the Protege list, which I felt was
appropriate since it seemed like the problem may have been on their end.  I
picked the pellet list and the OWL dev because you suggested that it would
be relevant to them.  I was not intending to cross post randomly or
spitefully.  In the future I will post separately.

I do think that Pellet is a great product, and I do respect the work that
you are doing with it.  Again, I apologize for the headache.

--Stephen




On 8/30/07, Bijan Parsia <bparsia@cs.man.ac.uk> wrote:
>
> Cross posting trimmed. By saying I wanted you to move it to an
> appropriate public forum I did not thereby suggest that you go on a
> cross posting spree. A bit of sensible netiquette really goes a long
> way. As does, of course, simple etiquette.
>
> On 30 Aug 2007, at 19:19, Stephen Larson wrote:
>
> > Bijan,
> >
> >    Sorry for not using the appropriate channels before.  I have
> > included other lists on this because I think that it is important
> > to clear this up.
> >
> >    I'm sending you the simplest example of this problem that I can
> > find.  It doesn't seem to happen with a single simple case of the
> > presence of a boolean.  The behavior appears to be more complex
> > than that.  But it is the case that the problem exists, I've sent
> > you an example ontology that exhibits it, and it can be reversed by
> > commenting out the booleans.  It is reproducible if you use the
> > tools that I have described.
> >
> >    I understand if you are frustrated with the DIG interface.
>
> I don't think you do.
>
> > But, it seems like you are implying that Pellet doesn't really
> > support the interface.
>
> Well, no. But I say now that it seems that you don't really
> understand the limitations of the DIG (1.1) interface.
>
>         <http://dl-web.man.ac.uk/dig/2003/02/interface.pdf>
>
> """This Level 0 Version 1.1 provides rather restricted support for
> concrete domains.
> Integers and strings are provided, along with concept expressions for
> minimum, max-
> imum, value equality and ranges. Linear inequations are not provided,
> nor are
> named concrete objects, although these will be introduced in a later
> version of the
> schema. Ranges can be asserted for attributes using assertions like
> rangeint or
> rangestring. If no range is supplied, attributes have integers as
> their range by
> default.
> """
>
> The error you got, IIRC, claimed that that "False" is not an "int",
> which implies (to me) that the interface was coercing an unknown
> datatype to a known one. I admit that I haven't verified this
> directly, but you aren't encouraging me to do that work.
>
> As far as I know, Pellet is DIG compliant. It's possible that there
> are bugs, but I believe that what you are hitting is a known problem
> in the DIG specification.
>
> >    I'm just a naive user here with limited resources.
>
> Whereas I have unlimited resources which I'm more than glad to put at
> your disposal.
>
> >   I'd like to use Pellet to check out my ontology in Protege 3.3.1
> > without having to acquire a 'toolchain' in order to do it.
>
> Protege3.3.1 and Pellet *are a toolchain*. DIG is known to have issues.
>
> Dude, just test it out with FaCT++ under dig and see what you get. My
> bet is a similar response.
>
> > The pellet website says it supports DIG: http://pellet.owldl.com/
> > faq/protege/.  But it seems like maybe it doesn't really.
>
> Eh, your insinuations grow wearisome. I pointed you to more robust
> alternatives. I could point out that DIG 2.0 is underdevelopment to
> address these and similar issues.
>
> >   So it seems like the DIG interface is really just a distraction
> > and shouldn't be included in code intended for naive end-users.
>
> I never recommended to you that you use Protege 3.3.1 and DIG with
> *any* reasoner.
>
> >   Maybe some agreement between the Pellet and the Protege people to
> > stop supporting the DIG interface would be the best route to avoid
> > naive users like me from falling into these kinds of traps, getting
> > misleading error statements and thus being unable to fix their
> > ontologies so that Pellet can reason with them.
>
> Take it up with the Protege 3.3.1 folks. Protege4alpha shows that you
> can have a more reliable connection with a reasoner than DIG 1.1. I
> showed you several ways to work with your ontology for reasoning,
> e.g., OWLSight, which is better in a lot of ways as it supplies
> explanations as well.
>
> >   I think that would be best for the community.
>
> Yes, I'm sure you do think that.
>
> (If you wanted to do something constructive, you could add
> documentation to the Protege Wiki about limitations of the DIG
> interface...or even just start it, and solicit people to help. That's
> MUCH more constructive than this obnoxious, holier-than-thou, my-
> needs-are-superimportant moaning.)
>
> Cheers,
> Bijan "And of course I'm fallible and could have made a mistake in
> what DIG says or what's happening" Parsia.
>
Received on Friday, 31 August 2007 11:40:59 GMT

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