- From: Brian McBride <bwm@hplb.hpl.hp.com>
- Date: Fri, 28 Feb 2003 21:38:06 +0000
- To: Graham Klyne <GK@ninebynine.org>, Bijan Parsia <bparsia@isis.unc.edu>
- Cc: www-rdf-comments@w3.org
At 13:03 25/02/2003 +0000, Graham Klyne wrote: >Bijan, > >Thank you for your comments. I think your preference here is clear >enough, without paraphrasing: > >[[ >>Section 4 of Concepts and Abstract should be struck. >]] > >This issue has already been raised, and is subject to some debate, and, >without prejudicing the outcome of our debate, I'm pretty sure there will >be some big changes. > >Brian: do we need to raise a separate issue for this, or can we tag it >onto an existing one? (Your call.) I think this is another expression of concern over the social meaning issue. I've added a link to this thread under that issue: http://www.w3.org/2001/sw/RDFCore/20030123-issues/#pfps-14 Brian >#g >-- > >At 12:02 AM 2/22/03 -0500, Bijan Parsia wrote: > >>Section 4 of Concepts and Abstract should be struck. >> >>I have a general argument for this, as well as some specific ones. >> >>The general one is that specifying the interaction between "social" and >>formal meaning, heck, just specifying much of anything about social >>meaning is an INCREDIBLY hard task. So either this section is vacuous >>(i.e., it doesn't really specify anything and thus can be ignored) or >>it's dangerously underthought and underspecified. >> >>This is aside from the fact that the W3C is probably, by ordinary social >>conventions, the wrong authority to be specifying "social" meaning. For >>example: >> """Human publishers of RDF content commit themselves to the >> mechanically-inferred social obligations.""" >> >>Does this mean, "Hey there, by the laws of the US and most countries of >>the world, if you publish RDF on your website, then you're committed to >>the mechanically-inferred social obligations"? If so, it's merely >>informative (and, in fact, probably false). If it's intended to *make it >>so*, then where do you get this authority? >> >>Goodness, have any lawyers looked at this? >> >>I mean, the fact that you have written "mechanically-inferred" is >>*itself* scarily sloppy. After all, that's reasonably interpreted as *any >>inference drawn by a program*, regardless of whether its using RDF(S) >>entailment or not! >> >>------- >>Detailed comments: >> >>***Section 4: >>"""There are two aspects to the meaning of an RDF graph. There is the >>formal meaning as determined by the RDF semantics [RDF-SEMANTICS]. This >>determines, with mathematical precision, the conclusions that can >>logically be drawn from an RDF graph.""" >> >>Do you mean that only RDF(S) entailments can be logically drawn from an >>RDF graph? That's wrong, as with an OWL reasoner I can draw more >>conclusions. And, if we interpret logically strongly, e.g., as >>"reasonable" (distinct from formal) then I can logically draw *all sorts* >>of conclusions from an RDF graph that aren't sanctioned by the Semantics. >> >>"""There is also the social meaning of the graph. It is the social >>meaning that affects what it means to people and how it interacts with >>human social institutions such as our systems of law.""" >> >>To the exclusion of the formal meaning? Yet 4.4 explicitly connects them. >>Indeed, if correct, 4.4 establishes a certain social meaning of an RDF >>graph (which includes the social meaning of the formal implications of >>the *formal* meaning of the RDF graph). >> >>***Section 4.1: >>"""RDF/XML expressions, i.e. encodings of RDF graphs, can be used to make >>claims or assertions about the 'real' world. Such expressions are said to >>be asserted.""" >> >>I'm scared that you use scare quotes for 'real'. I just don't know how to >>interpret that. Further more, this section doesn't say HOW one asserts >>with RDF expression. Also, it's reasonable to say that only RDF/XML >>expression can be used to make claims or assertions. But presumably the >>*graphs* are the primary carriers of meaning? >> >>The second paragraph makes more claims about unasserted graphs with no >>specification of when graphs are asserted and *how one fixes the meaning >>of the asserted graph*. I mean *fix* it, to a *specific* grounded >>interepretation. >> >>***Section 4.2: >> >>"""When an RDF graph is asserted in the Web, its publisher is saying >>something about their view of the world. """ >> >>Again, how do I assert a graph (or *not* assert) a graph "in" the Web? >>Also, in general if *I* assert something, I'm typically saying something >>about *the world*, not my view of it. Also, a publisher may not be, and >>may *typically* not be the asserter. Indeed, what is it to be the >>*publisher*, in this context? The ISP? The web hosting company? The >>author of the document? >> >>"""Such an assertion should be understood to carry the same social import >>and responsibilities as an assertion in any other format. """ >> >>Well, with HTML, I'm not committed to the mechanically-inferred >>conclusions of the HTML dom tree. So....? >> >>2.3 >>"RDF has a formal semantics which provides a dependable basis for >>reasoning about the meaning of an RDF expression. In particular, it >>supports rigorously defined notions of entailment which provide a basis >>for defining reliable rules of inference in RDF data." >> >>Hmm. A formal semantics does make it easier to reason about the *formal* >>meaning of an RDF expression. It also makes it easier to reason *with* >>that expression (which I take the second sentence to express). It doesn't >>help with social meaning, though, contrary to 4.4: >> >>"""The meaning of an RDF document includes the social meaning, the formal >>meaning, and the social meaning of the formal entailments. The assertion >>of an RDF graph G, when G logically entails G', includes the implicit >>assertion of G'. The implied assertion of G' should be interpreted using >>the same social conventions that are reasonably used to interpret the >>assertion of G.""" >> >>My reaction to this is, "Wow, that's *CRAZY*!!!!" I do not exaggerate. >>There's also a bunch of inconsistency in that section, for example: >> >>4.2: """Such an assertion should be understood to carry the same social >>import and responsibilities as an assertion in any other format.""" >> >>But the normal social import and responsibilities of an assertion in HTML >>is *not* the social import and responsibilities of the *formal* >>entailments (especially not the FOL entailments of an RDF regimentation >>of) that HTML. (For one, I'd rather be committed to the relevant >>implications of my statments.) Plus, consider the common social meaning >>of Moore's paradox: "I don't believe it's raining". >> >>""""A combination of social (e.g. legal) and technical machinery >>(protocols, file formats, publication frameworks) provide the contexts >>that fix the intended meanings of the vocabulary of some piece of RDF, >>and which distinguish assertions from other uses (e.g. citations, denials >>or illustrations).""" >> >>Well, in a *normative specification*, I would expect this combination to >>be spelt out. It isn't. >> >>Plus, *intended* meanings, by their nature *ALWAYS* can come unstuck from >>the conventions and formal/techincal structures of the meaning carrying >>expression. How does speaker's meaning (vs. sentence meaning) come into >>play. If I *intended* to refer to John when I say Mary, what have I done >>from the RDF point of view? >> >>There's a large philosophical literature on this. At best, you can hope >>to fix the *sentence* meaning. >> >>"""The social machinery includes the form of publication: publishing some >>unqualified statements on one's World Wide Web home page would generally >>be taken as an assertion of those statements. """ >> >>Generally. And if not so taken? Is it *correct* to so take? On what >>ground? In which juristiction? How is this normative? >> >>"""But publishing the same statements with a qualification, such as "here >>are some common myths", or as part of a rebuttal, would likely not be >>construed as an assertion of the truth of those statements. Similar >>considerations apply to the publication of assertions expressed in RDF.""" >> >>Be construed. By whom? Speaking as someone who's *often* misread (e.g., >>as asserting things I explicitly deny), what other people *construe* of >>what I assert is very far from determinative of what I assert. >> >>"""An RDF graph may contain "defining information" that is opaque to >>logical reasoners. This information may be used by human interpreters of >>RDF information, or programmers writing software to perform specialized >>forms of deduction in the Semantic Web.""" >> >>Again with the scare quotes. Scare quotes are used to indicate that the >>enclose words are not being used in their normal sense. But there's no >>vague, much less precise, definition of "defining information". And I'm a >>logical reasoner, will this information be opaque to me? (Well, if in >>German, yes, but *all* human reasoners?) >> >>***4.3: >> >>""The social conventions surrounding use of RDF assume that any RDF URI >>reference gains its meaning from some defining individual, organization >>or context. This applies most notably to RDF predicate URI references.""" >> >>Actually I presume that people do the presuming. And are these social >>conventions true in all societies? Are you reporting, or specifying? >> >>""""Thus, the choice of terms used in published RDF is significant in >>determining its meaning, through reference to definitions asserted by the >>defining authorities for those terms.""" >> >>How does this fit in with my ability to use any URI in my ontology, >>making any defining assertions I like about it? >> >>""""However, even when a URI reference can be dereferenced as an RDF/XML >>document, it's use within an asserted RDF graph does not implicitly >>assert the contents of the referenced document."""" >> >>So it's formal meaning isn't fixed IN ANY WAY by the "authority"? And the >>social meaning? >> >>***4.4 >> >>"""Human publishers of RDF content commit themselves to the >>mechanically-inferred social obligations."""" >> >>I discussed this above. It's also unclear what the mechanically-inferred >>*social obligations* are (as opposed to the mechanically inferred *formal >>entailments*). >> >>"""The meaning of an RDF document includes the social meaning, the formal >>meaning, and the social meaning of the formal entailments. The assertion >>of an RDF graph G, when G logically entails G', includes the implicit >>assertion of G'. The implied assertion of G' should be interpreted using >>the same social conventions that are reasonably used to interpret the >>assertion of G.""" >> >>Oh, this might fix it. But what if the social meaning of the set of >>explicit assertions is different from the set of those of the set of >>implicit assertion? heck, if people general work with a relevance logic >>(more likely than RDF entailment), then you *explicitly* don't always >>endorse/believe P & ~P even if you assert/believe each conjunct separately. >> >>Finally, if I assert a contradiction (which I can do, *even in rdf*), am >>I thereby commmited to the social meaning of EVERYTHING? >> >>Oops, out of time. >> >>Cheers, >>Bijan Parsia. > >------------------- >Graham Klyne ><GK@NineByNine.org>
Received on Friday, 28 February 2003 16:37:04 UTC