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Fwd: Certification of OWL 2 tools via OWLlink?

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Date: Mon, 26 Jan 2009 03:54:59 -0500
Message-ID: <29af5e2d0901260054m13876034i645e5e0fe7810e74@mail.gmail.com>
To: public-owl-comments@w3.org
Forwarded by permission:
"please feel free to forward this to wherever you think it is
appropriate (and does not disturb the wonderful work on OWL 2 too

---------- Forwarded message ----------
From: Marko Luther <luther@docomolab-euro.com>
Date: Tue, Jan 20, 2009 at 6:19 AM
Subject: Certification of OWL 2 tools via OWLlink?
To: ian.horrocks@comlab.ox.ac.uk
Cc: Alan Ruttenberg <alanruttenberg@gmail.com>

Dear Mr. Horrocks,

I was just reading in the latest OWL 2 PhC Minutes on
<http://www.w3.org/2007/OWL/meeting/2009-01-14> the line

"Ian Horrocks: important to get comments from companies and
organizations outside the working group"

Evaluating the potential use of the OWL/DL technology in the
(mobile-)industry I feel pushed to write you. Wrt. the limited time I
am able to spend on OWL it is not possible for me to provide any
valuable comment on the rather large and complex OWL 2 specification.
However, I would like to make a comment on OWL 2 from my perspective.

Besides that the benefits of the OWL technology are rather difficult
to communicate to development departments because of its overall
complexity (I really enjoyed your OWL article in the Communication of
the ACM 12/2008), we discovered many issues (such as purely syntactic
issues, wrong answers, non-termination, incomplete coverage) in the
currently available tools (OWLAPI, Protege4) and reasoners (Pellet,
RacerPro, FaCT++, HermiT) lately. Some could be identified as just
interfacing issues, others were revealing issues within the reasoning
kernel (mostly errors in the implementation of optimizations I
assume). Some of the issues were even reoccurring in later versions
once fixed.

Under the assumption that the (commercial) availability of reliable
tools is important for such a technology to be successful in
industrial applications, I think that the idea of a certain
certification process is important. Is this the idea behind the OWL 2
tests currently collected at


Why not combining these correctness test with automatic performance
tests along the line of your work presented at DL'06 [1]? This could
give "customers" at least an idea of which reasoning engine best to
use for their application. Being aware, that the tool described in [1]
is based on the outdated DIG protocol that not even cover all of OWL
1, I wonder if the OWL 2 WG ever discussed the importance of a
standardized communication protocol that, in contrast to the OWLAPI,
is implementation-neutral and goes along the language specification
such as the OWLlink protocol the DIG 2 coalition proposed in [2]. In
[1] it is stated that the best (and perhaps the only) way to check
correctness of reasoner engines on larger real-world examples is often
by checking for consistency with the reasoning of other existing
systems. I agree, but also wonder if the current approach to verify
the elements in the test queue
is to run the reasoners from within the OWLAPI. The advantage of using
OWLlink instead for providing a generic benchmarking suite is that
this way one does not depend on the OWLAPI interpretation (and correct
implementation) of OWL 2 as OWLlink relies directly on OWL 2 for the
primitives of the modeling language. A second advantage is that
OWLlink can be directly supported by engines outside the scope of the
Java world. Is it planned that OWLlink (after its final alignment to
the final OWL 2 specification) will get the status of W3C Note (as it
is planed now for the ManchesterSyntax) or will it at least be
somewhere mentioned in a description of the existing OWL 2 universe?

Best Regards,
Marko Luther

[1] Tom Gardiner, Ian Horrocks, and Dmitry Tsarkov. Automated
Benchmarking of Description Logic Reasoners. In Proc. of the 2006
Description Logic Workshop (DL 2006), 2006.
[2] T. Liebig, M. Luther, O. Noppens, M. Rodriguez, D. Calvanese, M.
Wessel, M. Horridge, S. Bechhofer, D. Tsarkov, and E. Sirin, "OWLlink:
DIG for OWL 2," in Proc. of the OWL Experiences and Directions
Workshop at the ISWC'08, November 2008.

Received on Monday, 26 January 2009 09:09:35 GMT

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