- From: pat hayes <phayes@ai.uwf.edu>
- Date: Fri, 1 Jun 2001 17:20:21 -0500
- To: las@olin.edu
- Cc: www-rdf-logic@w3.org
>Jonathan Borden wrote: > > > Sandro Hawke wrote: > > > > > > For example, here are 7 facts: > > > 1. I can imagine a condition, X. > > > 2. X can be expressed accurately as English sentence Y. > > > 3. Y has four words. > > > 4. The first word of Y is "the". > > > 5. The second word of Y is "sun". > > > 6. The third word of Y is "is". > > > 7. The fourth word of Y is "shining". > > ... > > > Do you have any problem with this approach, beyond style? > > > > My problem with this approach is this: > > > > In order to decide the truth of any statement "X" I cannot simply test > > whether it is or is not a direct member of the set of Statements. If it is > > not a member, "X" might still be true, because it is inferred >from the other > > statements as you describe. > >This is essentially always true, unless you forbid inference and close the set >of sentences you're considering. What's important is what we (minimally) >require that you be able to tell/infer and what we (maximally) permit you to >infer and what we do about any discrepancy that (almost inevitably) remains >between the two. I don't see there being anything here to do with permissions or requirements. How can one website emit such constraints on another web agent's actions? There arent any guards here. > > So why say that statements are true just because they are members of this > > set? ... > > > To me, stating that each statement in Statements is a fact does not gain me > > anything (in ease of inferencing) and costs me alot (of cumbersomeness and > > confusion). > >Well, not "are true" and not "is a fact", but "is asserted by the >document", at >least, which may be the same as far as your concern goes. No, no. That is what "assert" MEANS. Look, if I assert (note: *assert*) the following sentence: "The sun is shining.", then while of course you are free to believe or disbelieve me, or indeed to draw all sorts of conclusions about me, it remains the case that what I said was that the sun was shining. That is not a sentence, but a claim about the way the world is: it is such as to make the sentence (that I asserted) true. You may observe me and correctly say "Pat asserted: "The sun was shining" " , much in the way that you might observe a frog and correctly say: "The frog said: "Graaak" ", but that observation does not constitute an exchange of content, and what you have asserted is not what I said. If we are having a conversation under normal rules of mutual cooperative communication, then a basic act of communication has taken place not when you make an observation about my utterance, but when you interpret the *content* of that utterance and accept it, ie when my asserting "the sun is shining" leads you to believe that the sun is indeed shining. I presume that the basic idea of RDF (and DAML and OIL, etc.) is that they are primarily intended to be used to convey content in roughly this way, though of course greatly simplified since it occurs between mechanical rather than human agents. The wide world being what it is, no doubt issues of trust and cynicism may well arise, but these surely are intended to be concerned with the *content* of what the RDF (etc.) is encoding, not about its *form*. If the primary goal of all this effort is just to enable one agent to send some symbolic shapes to another to enable the recipient to assert something of the form "A sent me the following string:"kdjglafldgfla" " , then there seems to be little point in the entire enterprise. > Certainly the >benefit (which is nonetheless present for some and in some applications) comes >at a cost (for those who buy into inference as a given). > >I am under the impression that assertion by the document of statements >contained within the document is a fundamental tenet of RDF and there's no >changing it without dropping RDF. Assertion is *not* the same as truth of all >statements or documents, It is the claim that they are true, however. The two are closely linked. > but it is certainly something one could question if >one were considering RDF or not RDF. And I might take your approach in this >respect if I were building a language from scratch. Pat --------------------------------------------------------------------- IHMC (850)434 8903 home 40 South Alcaniz St. (850)202 4416 office Pensacola, FL 32501 (850)202 4440 fax phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Friday, 1 June 2001 18:20:28 UTC