- From: Bijan Parsia <bparsia@isis.unc.edu>
- Date: Sat, 22 Feb 2003 00:02:06 -0500
- To: www-rdf-comments@w3.org
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.
Received on Saturday, 22 February 2003 00:02:05 UTC