>Re: nouns as relations:
>
>[Danny Ayers] > Had a convention appeared early on for the use of nouns with
>a
>> consistent polarity, then the simple noun approach described here
>> would make a lot of sense:
>>
> > http://esw.w3.org/topic/RoleNoun
>>
>> But as it stands, I'm not sure it's viable in the general case for the
>> reasons you give. I certainly get confused : I don't know whether it's
>> a linguistic pattern or just habit - "creator" seems clear to me, but
>> "father" could work either way.
>>
>
>That reference shows that there are still some people who think that nouns
>serve adequately as relation names, but I have seen enough confusion to
>think that that is a mistake.
>
>The origin of this usage may also owe something to databases, where nouns
>label the fields. There, it is relatively unambiguous, because we know
>which entity has the properties of the noun. But when we have a graph with
>two nodes and a relation between them, it is not obvious which node has the
>properties of the noun. The left-to-right arrangement in an RDF triple
>would suffice in that context, if we had a firm and universal convention,
>but we don't. So I would like to see the verbal naming of relations become
>the default. (01)
So, let me ask a political/social question. How
will you propose to arrange it that there is a
'default' that people use? You are, in effect,
wanting the entire planet to adopt an informal
convention for your convenience. This seems
unlikely to happen, no matter how great the
advantage would be. (02)
Pat Hayes (03)
>
>Pat
>
>Patrick Cassidy
>MICRA, Inc.
>908-561-3416
>cell: 908-565-4053
>cassidy@xxxxxxxxx
>
>
>> -----Original Message-----
>> From: ontolog-forum-bounces@xxxxxxxxxxxxxxxx [mailto:ontolog-forum-
>> bounces@xxxxxxxxxxxxxxxx] On Behalf Of Danny Ayers
>> Sent: Thursday, January 03, 2008 9:13 AM
>> To: [ontolog-forum]
>> Subject: Re: [ontolog-forum] predicates in RDF
>>
>> On 02/01/2008, Patrick Cassidy <pat@xxxxxxxxx> wrote:
>> > Just a little off-topic "cri de coeur" about the naming of relations:
>> >
>> > [Chris Menzel said]
>> > >
>> > > But why? "creator" in that example from the RDF documentation is
>> > > simply
>> > > short for "is the creator of", which corresponds almost exactly to
>> the
>> > > definition of "predicate" that you yourself provided.
>> > >
>> >
>> > Actually, in that document it is short for "has creator", which has
>> the
>> > opposite polarity from "is the creator of".
>> > This is an extremely easy-to-make misinterpretation when simple nouns
>> are
>> > used to name relations: the polarity could logically be defined
>> either way,
>> > and different people use it in different ways.
>> >
>> > I really, really wish people would just stop using simple nouns to
>> express
>> > relations, and always use a verbal form like "isTheCreatorOf" or
>> > "hasCreator" or "is_the_mother_of" because when a simple noun is used
>> there
>> > is time wasted trying to remember or recheck just what the intended
>> polarity
>> > was, and a significant probability that it will be used incorrectly.
>>
>> Had a convention appeared early on for the use of nouns with a
>> consistent polarity, then the simple noun approach described here
>> would make a lot of sense:
>>
>> http://esw.w3.org/topic/RoleNoun
>>
>> But as it stands, I'm not sure it's viable in the general case for the
>> reasons you give. I certainly get confused : I don't know whether it's
>> a linguistic pattern or just habit - "creator" seems clear to me, but
>> "father" could work either way.
>>
>> There's an additional problem with predicate naming when the implicit
>> inverse is brought into the picture. timbl suggests
>> (http://dig.csail.mit.edu/breadcrumbs/node/72) we only need a name in
>> one direction, a label for the predicate is adequate in the other. But
>> I'm pretty sure the direction suggested by the Role Noun pattern won't
>> be the obvious one in all cases.
>>
>> For what it's worth, when working with RDF I generally assume the
> > appearance of:
>>
>> <subject> <predicate> <object>
>>
>> in a graph (RDF Model) means:
>>
>> <subject> <predicate> <object>
>>
>> - appears in that model!
>>
>> This is enough for a lot of useful operations (e.g. SPARQL querying).
>> The rules for statement equivalence are easy enough to overlay, as are
>> those of RDFS and OWL (with caveats around the DL constraints).
>>
>> The things can also be viewed as Coddesque (binary) relations, but
>> from a pragmatic viewpoint that's just another arbitrary association
>> of the three parts to roles. Similarly the structure of the Web can be
>> overlayed - <subject> and <object> are resources in the sense of
>> WebArch (http://www.w3.org/TR/webarch/), and <predicate> is a
>> (possibly typed) link between them. I believe the RDF MT is consistent
>> with this view of WebArch, at least if it isn't I've not noticed any
>> undesirable side effects. (Ok, there seem to be some weird
>> disconnects, but no obvious contradictions).
>>
>> I am not a logician, and don't need to be, now Pat et al have got that
>> stuff in place. The naive approach above seems to work fine as long as
>> the open world assumption is borne in mind (not too much, in practice
>> most of the time you're working against a locally-closed world), and
>> avoid any tendency to slip into object-oriented programming style (can
>> be tricky, when using the stuff in an OO language)...and for that
>> matter natural language linguistics.
>>
>> Cheers,
>> Danny.
>>
>> --
>>
>> http://dannyayers.com
>>
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