W3C home > Mailing lists > Public > public-sw-meaning@w3.org > May 2004

Re: Comment on "Named Graphs, Provenance and Trust"

From: Bijan Parsia <bparsia@isr.umd.edu>
Date: Tue, 11 May 2004 13:55:44 -0400
Message-Id: <6CEF1E28-A374-11D8-84C1-0003939CCC42@isr.umd.edu>
Cc: public-sw-meaning@w3.org, "John Black" <JohnBlack@deltek.com>
To: Pat Hayes <phayes@ihmc.us>

On May 11, 2004, at 1:22 PM, Pat Hayes wrote:

>> On May 6, 2004, at 3:11 PM, Pat Hayes wrote:
>> [snip]
>>>> This is what I previously referred to as a 'stipulative definition' 
>>>> or
>>>> 'stipulative ontology'.  What I am trying to get at intuitively is 
>>>> the
>>>> ability to say, "When this term is used in this context it SHALL be
>>>> interpreted to mean that".  And as a crude example of its use, 
>>>> imagine
>>>> I had need to import two ontologies, one a universal business 
>>>> language
>>>> ontology of commercial transactions, and the other, Bijan and 
>>>> Peter's
>>>> alternative ontology of transactions, both of which contained some 
>>>> terms
>>>> I needed but which had an incompatible "invoice" term that caused an
>>>> ambiguity (inconsistency).  Now I want to be able to eliminate the
>>>> ambiguity by stating that within this named graph, when the term
>>>> "invoice" is used, it SHALL be interpreted according to the UBL 
>>>> ontology
>>>> (or vice versa).
>>
>> (The above was from John Black.) Interestingly, John, this is exactly 
>> the kind of scenario we were interesting in making possible, even 
>> though the current tools (owl:imports, cut and paste, etc.) are a bit 
>> crude. The current canonical way to achieve this is to simply only 
>> include in your document the desired axioms. On some views (e.g., 
>> some variant's of Tim's view), it was much more difficult to exclude 
>> the URI owner's axioms.
>
> I don't think that interpretation was ever Tim's intended meaning 
> (I.e. the interpretation in which importing the URI owner's axioms was 
> kind of obligatory).

I do. At least, I have elicited such view from Tim (and distinct 
views...his line is much softer on this for quite a while), and from 
other people.

> You only get to that from what Tim was (I think) talking about by 
> imposing a very limited view of what 'meaning' means.
>
>> However, as pat point out, you can't stop me (currently, or really, 
>> ever) from adding yet more axioms to your set.
>
> Wait a minute. Look, a SET is a mathematical abstraction. It doesnt 
> make sense to speak of DOING something to a set.

Sigh. I meant Python Sets, which are mutable :)

> What you can add axioms to is a document or an ontology or some 
> concrete thing on the Web somewhere. So lets talk about those. I CAN 
> stop you adding axioms to MY document, and of course you can write 
> documents of your own out the wazoo, and can incorporate my axioms 
> into them (by reference or by cutting and pasting) and I can't do 
> anything about that.  All that is obvious.

Strange how it hasn't always been to some people in some conversations.

>> E.g., if I import *your* document, I'm almost surely going to add 
>> assertions, and I'm free to add axioms, even concerning your classes.
>
> Right, of course (does this ever need to be said again??)

Yes. Or, at least it's possible that it will have to be said again.

I was just starting from the obvious case. Trying to start from a point 
I felt confident we all agree on.

> but YOU are saying those axioms, (in YOUR document), right?

Yes.

> John isn't asserting them. So take a hypothetical third party, call 
> him Joe, who can read all this stuff. If Joe reads what Bijan 
> publishes he will get a potentially different idea than the one he 
> would get if he only reads what John publishes. Of course: so what? 
> Does that change the meaning of what John published? No. Does it 
> change the meaning of John's terms as used by Bijan? Seems to me it's 
> up to Joe to decide that. If Joe believes Bijan as well as John, then 
> the meaning of the terms is determined by (Bijan's ontology + John's 
> ontology) as far as Joe is concerned. What if John protests that his 
> terminology is being misused by Bijan. Well, he may be right.

Sure. Though, I don't want to be told that my misuse is a matter of 
Web/RDF/OWL architecture or standards. I want to be able to do the 
analogue of deep linking. I want to use your URIs and make a slew of 
assertions involving them. If you've, from my perspective, published 
crap about the URI at some relevant web location, I don't want to have 
any technical pressure at all for including it. I don't want to have to 
keep delving into nasty preference files, etc. etc. I think this 
inhibits reuse, personally.

>  Still, Joe can reply: OK, but I'm not only hearing you, I'm also 
> hearing Bijan. Suppose John admits that there's no way that he, John, 
> can stop Joe listening to Bijan, but still wants to restrict the 
> meanings of his terms *as intended by him* to be only the meaning that 
> can be inferred from his, John's, publication.

In his document. Neither Peter nor I have ever argued against anything 
like this. We've argued for it. But we want it to be the case for all 
document authors. I say what I say. If you want to combine what I say 
with what the "word (uri) owner" says, that's *your* lookout.

> That is about the best that he can do, seems to me, and that is what 
> our proposal allows him to do. It would enable Joe, if he were so 
> inclined, to discover that Bijan was using John's terms in ways that 
> violate John's intentions, and so (if he, Joe, were so inclined) to 
> follow John's intentions more accurately: it allows Joe to resist the 
> infection by Bijan of alien meaning into Joe's understanding of John's 
> vocabulary: again, all assuming that Joe is interested more in what 
> John says than in what Bijan says.
>
> However, all that said, it seems to me that what might be called the 
> normal case is one where everyone is kind of in broad agreement about 
> intended meanings, and everyone acknowledges that in a case of a clash 
> of meaning or intention, that the 'owner' or originator of a URI has 
> more social authority over the intended meaning than any other single 
> authority.

I think this is insupportable. I really do. Especially in the absence 
of the normal overrides for that authority.

Not in every case, but in many cases, especially casual reuse. Dan's 
example is compelling.

> There will be exceptions, eg if an entire community 'misuses' a term 
> in some way consistently, but such phenomena are familiar already and 
> we know, broadly , how to handle them.

Right. I don't want to preclude them with hamfisted legislating. I'm 
the quietist on all this, after all. Though I don't object to the kind 
of moves you make in your paper, in principle.

>> Even if I just add facts ("instances"), I can affect the *inferred* 
>> axioms (e.g., the classification). So the question becomes, how far 
>> reaching should your stipulations reach?
>>
>> I *like* being able to say, of my documents, that the axioms are 
>> *these* ones I put in some effort to put in, and not *those* which I 
>> put in some effort to exclude.
>>
>>> But the performative story only gives you a kind of act, not a 
>>> stipulation about other's acts or interpretations. So let me try to 
>>> rephrase this a little: suppose we say that the intuitive force of 
>>> such a stipulative definition is to declare that *your intention* is 
>>> that the terms shall have the meaning you give to them, and that any 
>>> usage (such as Bijan and Peter's, in the example) which clashes or 
>>> is incompatible with your meanings is not intended by you. This of 
>>> course does not *prevent* P & B from misusing your terminology (how 
>>> could it?) , or force anyone else to believe you rather than them 
>>> (so all this foolish
>>
>> Foolish stupid? Foolish tactically unwise? Foolish cute?
>
> Foolish stupid, since you put it that way. I think y'all are 
> misunderstanding the point.

Likewise, evidently :)

> Take the http GET protocol. This sets out detailed instructions about 
> exactly what must be done by browsers, network software and servers 
> when you click on a hyperlink in a Web page. This stuff is intensely 
> proscriptive: so does the HTTP spec oppressively limit the freedom of 
> software to act as it chooses? Is this tyranny in action? Well, if you 
> like, you could say that, but this would be a foolish conclusion.

No, but there are differences that make a difference. Clearly both 
Peter and I are find with normative specification and are totally 
inclined to be rather insistent about what you say an OWL document 
means. I find it to be a recurring irritation, going all the way back 
to the Boston tech plenary, that I am the object of such imputation. 
There *are* people who argue against standardized vocabulary in 
general, quite strongly. I'm not one of them, clearly.

>  In fact, it is false: I *could* write a browser which claimed its 
> right to treat hyperlinks differently, cast off the oppressive chains 
> of the HTTP protocol and act in its own proud individualistic way.

Pfft.
	or
:)

> It would just be a useless browser, of course, rather in the way that 
> human being who insisted on not believing anything told to it would be 
> a useless human being (we all know some of these, right?) and a SWeb 
> agent which refused to draw conclusions from any ontologies except 
> those directly indicated would be useless. The point is not that any 
> of these things are OBLIGED by some external tyrannical compulsion to 
> conform to any social convention, so much as the observation that if 
> they don't conform then they aren't going to be able to work very 
> effectively, particularly if everyone else is conforming: which is the 
> entire point of having the conventions in the first place.

We're worried about the nature of the conventions proposed. Some irk us 
and we think will irk others. They will be oppressive at least in the 
sense that some people (e.g., many Lispers) find programming in C++ 
oppressive. There is room, however, for worse on the semantic web.

>  If you approach any social system of communication with a basically 
> paranoid assumption that everyone is out to screw you,

It's not unreasonable to be concerned with various senses of security 
in a social system of communication, in *any* one.  There are special 
issues in a system involving significant automated processing in the 
midst of that communication.

>  and with the prime goal of avoiding infection by other's ideas and 
> meanings,

We're trying to avoid a situation where we feel compelled to act that 
way.

> then you are likely to not be able to communicate as effectively as an 
> agent which approaches communication with the intention of 
> communicating. You and Peter are adopting a stance of what might be 
> called semantic paranoia as a basic operating assumption of the SWeb, 
> which seems to me to get the entire thing backwards.

We argue for choice. I don't believe we do argue for semantic paranoia. 
If you want to import everything under the sun, go ahead. It seems to 
be a sane and familiar way to operate. Or if you are writing processing 
software, aggregated a bunch of claims into a kb and work on that.

>>> analogizing with tyranny, oppression and freedom is beside the point)
>> [snip]
>>
>> I dispute that it's (necessarily) a misuse, so perhaps the analogy, 
>> about which I was having a few qualms, is apt.
>>
>> The point of this discussion is how much de jure authority we are 
>> giving to URI owners.
>
> None whatsoever, in the sense that you seem to be understanding 
> 'authority'. No amount of web publication in any medium obliges any 
> reader to endorse, utilize or agree with any of it if they choose not 
> to: and this goes for software as much as it does for human agents.

If OWl, for example, required some form of ontological closure beyond 
the explicit on of owl:imports, then OWL compliant software will 
process my documents a certain way. I can, of course, avoid such OWL 
compliant software and perhaps require people not to process my 
document with OWL compliant software (at least, if they want me to 
accept the results). This seems worse than doing things the other way 
around, frankly.

>  This is just obvious. (So if someone seems to be saying something 
> that contradicts this, maybe you should contemplate the possibility 
> that you may have misunderstood what they were really saying.)
[snip]

Well, I was tempted to make a plea for charity several times earlier, 
but resisted. But frankly, this is beyond my willingness to bear at the 
moment. I'm totally surprised you would think that I need this advice.

Cheers,
Bijan Parsia.
Received on Tuesday, 11 May 2004 13:56:27 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Monday, 7 December 2009 10:42:16 GMT