[Attempto] RACE Web Service problem

[Kaarel Kaljurand]

Hi,

it's a bit difficult to answer without knowing the details.
Maybe you can send your exact input.

On Tue, Mar 24, 2009 at 8:43 PM, Calin Bindea <bindea.calin at gmail.com> wrote:

> I want to use ACE, particularly the reasoner RACE, as a natural
> language query interface to an ontology. The ontology was created using
> Protege and I converted it to ACE with the help of the "Ace View" plugin.

OK. But note that in addition to the ACE text you also have to store
the lexicon (which is shown in the "Lexicon format view" in ACE View).
Only then can an APE-based tool such as RACE interpret the words
in the text correctly.

> Using the resulted ACE statements I would like to provide the user with
> the possibility of issuing simple ACE language questions.

So, the resulted statements were all declarative, i.e. didn't contain any
questions?

> I tried to test
> using the RACE Web Service, but I keep getting an error:
> "time_limit_exceeded. Web service call failed". I only used 10 Axioms, which
> is a small part of the total number I wan't to use for the final version.

I tested now and also encountered the time limit error with RACE. I've
restarted the
service and now it runs faster. We will have to check what could have
caused this
slowdown.

> I also tried running the "Pellet" reasoner on OWL data obtained by first
> transforming to ACE, then adding the ACE query and then transforming again
> to OWL XML with the help of APE, but I get an error because it apparently
> can not transform ACE questions using "What" to OWL.

What was your exact question?

"What"-questions are supported by the ACE->OWL translation, e.g.

What does John see?

is translated into:

   SubClassOf(
      ObjectSomeValuesFrom(
         InverseObjectProperty(ObjectProperty(:see))
         ObjectOneOf(
            Individual(:John)
         )
      )
      Class(owl:Thing)
   )

But note that only AceWiki and ACE View know how to work with this
representation
of questions which basically packs the question (i.e. DL-query, i.e.
OWL class expression)
into an axiom where the question is the subclass and owl:Thing is the
superclass.
I.e. the question can be stored like this in OWL XML but Pellet would
not handle it as a question
but rather treat it as semantically redundant axiom.

There is no standard that says how to store DL-queries with OWL
ontologies, so that's why
we have had to use this kind of trick here.

In your case, if you want to use Pellet to execute the query then you
need to write
a little OWL-API based wrapper that maps this query representation to OWL-API
reasoner API call. You can look at the AceWiki and/or ACE View source code
to see how it's done.

> This project is part of my Bachelor degree assignment so I need to know as
> soon as possible if this approach can be used. Is there any way of running
> RACE locally? If not, how could I get around this problem?

Currently, RACE is not yet available for download. Norbert might give you more
information about the possible release dates and work-arounds till then.

Hope this helped,
Kaarel