Re: To embed or combine

> > The most important argument is that the embedding stands on its own feet,
> > while the combined semantics is of limited use, since we need the embedding
> > anyway.
> 
> We don't necessarily /need/ the embedding if we define a model-theoretic
> combination [*], it is just nice to have as an appendix, to show how
> reasoning can be done with the combination.  Just like, as you suggested
> in an earlier e-mail, we could use the model-theoretic combination in an
> appendix as a justification for choosing a particular embedding in case
> we go for the embedding.

Publish the semantics without the embedding, and see what the reaction will be.
I suspect that it will be: Huh? What do I do with this?

The point is that the embedding is trivial and easy to explain. 



> > Regarding (2) my argument was not what you wrote, but that Jos' document
> > essentially specifies a full-blown combined language. The embedding alone
> > is sufficient in my view. It allows people to use rules and RDF together,
> > but it does not define a normative combined language.  By defining an
> > embedding, we already achieve all the goals with respect to RDF, which were
> > listed in the charter.
> 
> Whether we define the semantics of the combination based on a model
> theory or based on an embedding in RIF, in both cases we define a
> combined language, which is normative.

You can put it this way, but then any embedding of any rule language into
RIF can be viewed as a combined RIF-LanguageX language. Normally people
will not view it this way.



	--michael  


> Best, Jos
> 
> > 
> > 
> > 	--michael  
> > 
> >> <chair>
> >> The status of the discussion regarding Jos' RDF compatibility section appears to 
> >> be mired in whether the normative semantics of RDF in RIF should be specified in 
> >> the model theory through a "combination" of RIF and RDF semantics, or through an 
> >> "embedding" of RDF semantics in RIF (as rules).  The two approaches have been 
> >> shown by Jos to be equivalent.
> >>
> >> At the moment I have not seen any technical arguments supporting one approach or 
> >> the other.  Michael prefers the "embedding" on the basis that:
> >>
> >> (1) the "combination" is more complicated than the "embedding" and thus more 
> >> difficult to understand.
> >>
> >> (2) it is not our job viz. our charter to specify a model theoretic approach to 
> >> the RDF/RIF combination
> >>
> >> Jos seems to prefer the "combination" and argues re: (1) that:
> >>
> >> (3) it is no more difficult to understand the "combination" than the RIF model 
> >> theory.
> >>
> >> As chair, my own read of the charter does not provide any particular help on 
> >> (2), I'm not quite sure what Michael is referring to there.  It is certainly our 
> >> job to specify how RIF and RDF should be used together, and as chair I interpret 
> >> this as meaning we should have a normative standard for that.
> >>
> >> Thus, as suggested by Michael, it seems to me we are at a difference in 
> >> preference only, and I see no alternative other than to call a vote.  It seems 
> >> to me the vote is about which approaches to make *normative*:
> >>
> >> 1) The model-theoretic "combination" of RIF and RDF is normative
> >> 2) The "embedding" of RDF semantics as RIF rules is normative
> >> 3) Both the "combination" and "embedding" are normative (What would that mean?)
> >> </chair>
> >>
> >> -Chris
> >>
> >>
> >> -- 
> >> Dr. Christopher A. Welty                    IBM Watson Research Center
> >> +1.914.784.7055                             19 Skyline Dr.
> >> cawelty@gmail.com                           Hawthorne, NY 10532
> >> http://www.research.ibm.com/people/w/welty

Received on Monday, 10 September 2007 08:00:21 UTC