[Person-ontology] D7 - Which languages are better than OWL?

[Gian Piero Zarri]

    Dear Philippe,

    While perusing your clever construction, I have noticed this 
particular 'opposition': "a representation using an n-ary relation can 
always be converted to a representation using a binary relation, without 
loss of semantics (pm)". The last syntagm of this sentence, "without 
loss of semantics", is false. We all agree about the fact that, from a 
pure formal point of view, any n-ary relationship with n > 2 can always 
be reduced, in a very simple way, to a set of binary relationships. I 
have discussed this sort of decomposition in several papers see, e.g., 
http://sunsite.informatik.rwth-aachen.de/Publications/CEUR-WS/Vol-166/63.pdf 
that you can freely download from the Web. This sort of decomposition is 
not only formally interesting, but could also be important for many 
practical problems, like storing efficiently n-ary relationships on 
databases or for interoperability's sake. Unfortunately, this fact does 
not change at all the intrinsic, 'semantic' n-ary nature of a simple 
statement like "Mary has given a book to Bill" that, to be understood, 
requires to be taken IN ITS TOTALITY. This means considering a semantic 
predicate of the "GIVE" type that introduces its THREE arguments, 
"Mary", "Bill" and "book" through THREE semantic relationships (roles) 
like SUBJECT (or AGENT if you prefer), BENEFICIARY and OBJECT, the all 
being SIMULTANEOUSLY MANAGED.

    In an European project of some years ago, CONCERTO, we have built up 
routines from converting the n-ary NKRL structures into and from RDF 
binary structures, to facilitate interoperability with the partners via 
the XML underlying substratum. Apart from some practical difficulties in 
order to make use of the (only three) RDF's 'containers' to represent 
the four basic NKRL's operators (ALTERN, COORD etc.), the operation has 
been perfectly successful with respect to the aim of having NKRL 
documents converted into RDF documents; I have some (old) papers on 
this. However, reasoning (i.e., inferencing) has always be NECESSARILY 
done in the original (n-ary) NKRL format - and, if I remember well, we 
have not been the only team to be obliged to adopt this 'round-trip' 
style of processing.

    Cheers,

    G.P. Zarri

     

mail at PHILIPPEMARTIN.COM wrote:

>Hi all,
>
>I have explicited, normalised and organised the assertions
>behind Gian's "quick, incomplete and disorganized comments" 
>and Jim's follow-up note about the goal of OWL.
>Below are the resulting structures (if your email client 
>does not show indented structures, please see their integration
>in the wiki at http://krl.wiki-site.com/index.php/Main_Page or 
>to the static page at http://www.phmartin.info/suo/). 
>These resulting structures (or their assertions) allow you to give 
>rationales for or against the many classic unargumented assertions
>that have been made.
>Hence, this is a good start for the discussion.
>I added some objections (see the relations by "pm"). 
>If I misinterpreted some assertions, please correct them.
>
>Philippe
>
>=============================================================
>
> "exchanging_ontologies_via_OWL does not require that `OWL is a good general_KRL'"
>   argument:
>    ("exchanging_ontologies_via_OWL is not detrimental to
>      knowledge_representation_or_inferencing_with_a_language_more_expressive_than_OWL"
>        objection: - "exchanging_ontologies_via_OWL may lead to a loss of semantics"(pm)
>                   - ("some applications require (or provide better results with)
>                       precisions that cannnot be represented via OWL"
>                         generalisation: "applications requiring precision need 
>                                          the expressivity" (pm)
>                     )(pm)
>    )(jrSchoening);
>
>
>
> "no W3C_language is a good_general_KRL"
>   specialization: "OWL is no a good_general_KRL" (gpZarri),
>   argument: - "no W3C_language is a KRL_with_n-ary_relations" (gpZarri)
>             - "a good_general_KRL should be a KRL_with_n-ary_relations" (gpZarri);
>
> "a good_general_KRL should be an expressive_KRL"
>   specialization:
>     ("a good_general_KRL should be a KRL_with_n-ary_relations"
>         argument:
>           - ("many applications would benefit from a KRL_with_n-ary_relations"
>                specialization: "Semantic Web Services would benefit from
>                                 a KRL_with_n-ary_relations"
>             )(gpZarri),
>           - ("a knowledge_representation_with_binary_relations cannot be as good as
>               a knowledge_representation_with_n-ary_relations"
>                 objection: "a representation using an n-ary relation can always be 
>                             converted to a representation using a binary relation
>                             without loss of semantics"(pm),
>                 opposition: "a knowledge_representation_with_binary_relations is better
>                              than a knowledge_representation_with_n-ary_relations"(pm)
>             )(gpZarri)
>     )(pm);
>  
> "a knowledge_representation_with_binary_relations is better
>  than a knowledge_representation_with_n-ary_relations"
>   argument: - "a knowledge_representation_with_binary_relations explicits
>                concepts and relations that are implicit in a 
>                knowledge_representation_with_n-ary_relations"
>             - "the more explicit the knowledge_representation, the better for
>                knowledge matching"(pm),
>             - "knowledge matching supports knowledge comparison, retrieval and
>                inferencing"(pm);
>
>
>
> "most practical_applications do not require a language as restricted as OWL"
>   specialization:
>     ("most practical_applications requires a language more expressive than OWL"
>        argument: - "a practical_application requires the use_of_rules"(gpZarri)
>                  - "the use_of_rules is hard with a DL"(gpZarri),
>        argument: "any notation for OWL can only be ugly and verbose"(gpZarri),
>        argument: "OWL is difficult for an average programmer to deal with"(gpZarri),
>        argument: ("OWL has been a flop from a concrete/commercial viewpoint of view until 2007"
>                     argument: "THIS was acknowledged by the IEEE Intelligent Systems issue 
>                                of September/October of 2007"(gpZarri)
>                  )(gpZarri),
>         argument: ` "DL-Safe-SWRL is decidable" has for consequence
>                     "SWRL variables can only be bound to known individuals in a KB" '(gpZarri),
>         argument: ("expert systems of the seventies were more interesting than OWL"
>                      argument: "in 2007 the best way to use rules along with a DL-language is to
>                                 to re-use an expert system such as via Jess or Algernon"(gpZarri)
>                   )(gpZarri)
>     )(pm),
>   argument: "most programmers do not care about computational_tractability"(gpZarri),
>   argument: ("RDF is probably more useful than OWL from an 'applicability' viewpoint"
>                argument: ("several commercials_products use RDF and not OWL"
>                             example: "Oracle_11g_RDF_database uses RDF and not OWL"(gpZarri),
>                             example: "GroupMe! and not OWL"(gpZarri)
>                          )(gpZarri),
>             )(gpZarri);
>
>
>
> "the SUO endeavour includes setting up a better alternative to OWL"(gpZarri)
>   argument: "most practical_applications requires a language more expressive 
>              than OWL"(gpZarri);
> 
> "the SUO endeavour requires more than informal_on-line_discussions"
>   argument: - "the SUO endeavour requires at least one 
>                                 building_of_a_significant_application"(gpZarri)
>             - "the building_of_an_application requires more than
>                                          informal_on-line_discussions"(gpZarri)
>             - "the building_of_significant_application requires money"(gpZarri)
>             - "the building_of_significant_application reuires to meet each other
>                                                          face to face"(gpZarri);
>
>  
>