W3C home > Mailing lists > Public > www-tag@w3.org > June 2011

Re: Issue-57

From: Alan Ruttenberg <alanruttenberg@gmail.com>
Date: Wed, 15 Jun 2011 04:25:45 +0100
Message-ID: <BANLkTimTYwOQiD37d0pgtTEpKhD=Bv+Jaw@mail.gmail.com>
To: David Booth <david@dbooth.org>
Cc: Jonathan Rees <jar@creativecommons.org>, Jeni Tennison <jeni@jenitennison.com>, "www-tag@w3.org List" <www-tag@w3.org>
On Wed, Jun 15, 2011 at 3:39 AM, David Booth <david@dbooth.org> wrote:
> On Wed, 2011-06-15 at 00:49 +0100, Alan Ruttenberg wrote:
>> On Tue, Jun 14, 2011 at 9:41 PM, David Booth <david@dbooth.org> wrote:
>> > On Tue, 2011-06-14 at 05:05 +0100, Alan Ruttenberg wrote:
>> >> On Mon, Jun 13, 2011 at 9:50 PM, David Booth <david@dbooth.org> wrote:
>> >> > I do not think that is a fair characterization.  Richard's example is
>> >> > *not* opting out of machine inference.  It is merely opting out of
>> >> > certain inferences that *some* applications need but others do *not*
>> >> > need.  And that is as it *should* be, as it is not possible to cater to
>> >> > *all* applications.
>> >> >
>> >> > The subtle mistake that is being made repeatedly here is in assuming
>> >> > that someone's data is *wrong* (or socially irresponsible) if it
>> >> > conflates two things that we humans find useful to distinguish, such as
>> >> > people versus web pages -- *even* if the class of applications for which
>> >> > that data is intended have no need to make such a distinction!
>> >>
>> >> Pat has it right:
>> >>
>> >> On Tue, Jun 14, 2011 at 4:33 AM, Pat Hayes <phayes@ihmc.us> wrote:
>> >> > Bear in mind that the very first principle of the Web is that the
>> >> > *publisher* of the data, who asserts these things about dogs or
>> >> > pictures of dogs, cannot possibly know what 'context of use' is
>> >> > going to be relevant to the *user* of the published content
>> >>
>> >> http://lists.w3.org/Archives/Public/public-lod/2011Jun/0199.html
>> >
>> > I agree with the above comment: data publishers cannot know how their
>> > data will be used.  However, that is *not* the same as saying that their
>> > data must be usable in all possible applications.  Any given dataset
>> > supports a particular class of applications and will be unsuitable to
>> > others.  For example, a dataset that models the world as flat may be
>> > fine for computing driving directions but would be unsuitable for
>> > aircraft applications.
>> David, each time a criticism is made, the response seems to switch to
>> responding to something different and not pertinent to the criticism.
> Apparently what you consider pertinent differs from what I consider
> pertinent.
>> Above you say:
>> "the class of applications for which that data is intended" = data is
>> published with an application in mind. Then you say you agree with Pat
>> that: "the *publisher* data, who asserts these things about dogs or
>> pictures of dogs, cannot possibly know what 'context of use' is going
>> to be relevant to the *user* of the published content"
>> These two statements are inconsistent. Either the data is published
>> with the intent that it be used in some applications and not others,
>> or the data is published without the user knowing the applications.
> No, they're not inconsistent.  To clarify: data is generally designed
> with an intent in mind, even though the publisher ultimately cannot know
> how the data will actually be used.  Furthermore, the data only
> *supports* a particular class of applications -- regardless of the
> publisher's intent.  Does that make more sense?

Not really, no. The intent is generally to communicate. That the data
only supports a some applications seems a trivial consequence of the
open world assumption. If an application needs some data and it isn't
there then it can't do what it wants to do. So it goes. I don't know
what a "a particular class of applications" means. Is that different
than "a class of applications"? Applications are constantly being
written - we can't even imagine what they will do as time progresses.

>> The shift in response is you talking about how it isn't the case that
>> "data must be usable in all possible applications" instead staying
>> with the point about your statements about users aiming their data at
>> certain application.
> I don't understand your point.

A statement that one shouldn't expect data to be usable in all
possible applications does not answer the question of whether data
publishers do or should "aim their data" at specific applications when
web publishing.

> I was pointing out the inevitability of users aiming their data at certain kinds of applications.

That doesn't follow. And this contradicts Pat's assertion again, which
you say you agree with. Perhaps you mean the inevitability that not
all applications will work on all data that is published. That doesn't
have anything to do with the user "aiming their data".

> I.e., it is not possible to design a dataset that is usable in all possible applications.

How is this relevant to the discussion point? We're talking about
whether users even design their datasets to be used in particular
applications in the first place, which is contested, as a matter of
practice and as a matter of policy.

>> Perhaps in you will respond that there is some essential ambiguity
>> that allows what you say to be inconsistent for *my application* which
>> uses logic to assess whether what someone is saying is coherent, but
>> is fine for *your application* which has some other goal?
> No, I don't think I'll try to do that.
>> But the bottom line is that I don't think your arguments hold
>> together, with the above sort of thing being just one example of a
>> pattern I see.
> Well, I've clarified the example above.  Does that help?

I wish I could say yes.

>> I come to the same conclusion about your next response. I was talking
>> about Richard's set of inconsistent assertions regarding documents and
>> people. You supported Richard: "Richard's example is *not* opting out
>> of machine inference.....".
>> But then you agree with me that Richard *isn't* free to change the
>> rules as he goes. Certainly uri owner for "foaf:Document" did not
>> intend that it be applied to a person.
> Oh, I think I see what you're talking about.  I assumed from memory that
> the FOAF ontology does not define foaf:Document to be owl:disjointWith
> foaf:Person.  And in checking the FOAF ontology now at
> http://xmlns.com/foaf/spec/index.rdf
> AFAICT my memory was correct: they are *not* defined as disjoint
> classes.

It doesn't matter if the disjoint is stated. Read the english. Ask
Dan. foaf:Documents are not foaf:Persons no matter what the axioms
currently say.

> However, you seem to be reading beyond what the FOAF ontology says to
> further divine the *intent* of these classes from the comments in the
> documentation, such as:
> http://xmlns.com/foaf/spec/#term_Person
> [[
> The Person class represents people. Something is a Person if it is a
> person. We don't nitpic about whether they're alive, dead, real, or
> imaginary.
> ]]
> and from those informal comments, you appear to be adding an implicit
> *formal* disjointness assertion that the ontology definition did *not*
> make.

I am saying that the intended meaning of the authors of foaf is that
no thing is at the same time a document and a person. It is the
omission of the disjointness assertion that an oversight. That the
comments say more is not an oversight. If there was a choice of what
to fix, the authors would modify the axioms, not weaken the comments.
And if you don't want to believe that I am able to "divine" the intent
then ask them.

> That certainly is a very reasonable assertion to add, and it is one that
> I would expect any application needing to distinguish between
> foaf:Documents and foaf:Persons to make.  I do not know whether the FOAF
> designers *intentionally* omitted this assertion -- perhaps to
> facilitate the use of FOAF by applications that do not need to
> distinguish foaf:Documents from foaf:Persons -- or whether it was
> omitted by accident.

Please ask them. They are around. You do not need to guess.

> But AFAICT, that disjointness assertion is *not*
> expressed in the formal FOAF ontology.  So I do not think it is fair to
> claim that *Richard's* data is contradictory or does not support
> inference just because it fails to assume an additional assertion that
> the FOAF ontology did *not* make, but *you* think it should have made or
> meant to make.

You are like the billionaire who, on being called out for not paying
taxes, says that no laws were broken because every tax loophole was a
legitimate loophole. Yet they have violated the social contract
nonetheless. And the reaction is not to say, "no, the social contract
is not to pay your share, it is to listen to exactly what the lawyers
say".  The reaction is to close the loopholes.

> There are two reasons why I do not think that such informal comments
> should be used in assessing whether a dataset is formally consistent.
> 1. They cannot be machine processed, and thus any requirement that they
> be considered would not scale well.
> 2. Different users will interpret them differently, and this would lead
> to confusion and interoperability problems.

They aren't being used to assess whether the dataset is formally
consistent. They are being used to assess whether the dataset is
consistent. We try to make the former match the latter, not say the
latter is irrelevant.

>> So again I see a contradiction. And the shift to a different topic.
>> First your respond about schema.org, which wasn't relevant to the
>> point, as they are not a data publisher. Second you write  "HOWEVER, a
>> URI declaration or definition cannot remove all possible ambiguity,
>> not matter how precise or well considered it is.". But *no one at all*
>> has said that document and person are defined in ambiguous enough ways
>> that they might be ambiguously used to mean the other.
> AFAICT, that is *exactly* how the FOAF ontology is defined, as explained
> above.  Indeed, ontology experts often warn against over constraining an
> ontology, as it limits its potential applications.

You continue to insist that the axioms trump the intent. It's as if
you were having a conversation but insisting on not understanding what
anybody says because you happen to only have an abridged dictionary on

I don't know many ontology experts. Many people who say they are are
most certainly not.


>> This pattern of discourse makes it very difficult to engage you. The
>> discussion is disjointed because of these contradiction/shift moves,
>> but it's distracting to have to break stride in an otherwise reasoned
>> conversation to analyze and document exactly what is wrong with the
>> responses.
>> I'm sorry this isn't a happy message, but that's my experience here.
> Sorry it's been difficult, and I hope the above explanation helps to
> clarify things.  And hard as it is, I think we're covering some
> important ground that needs to be discussed.

> --
> David Booth, Ph.D.
> http://dbooth.org/
> Opinions expressed herein are those of the author and do not necessarily
> reflect those of his employer.
Received on Wednesday, 15 June 2011 03:26:36 UTC

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