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Re: [ontolog-forum] is-part-of: a really, really, bad practice?

To: <ontolog-forum@xxxxxxxxxxxxxxxx>
From: jmcclure@xxxxxxxxxxxxxx
Date: Mon, 20 May 2013 16:43:23 -0700
Message-id: <4c3d5d92d9627278a3cf8f43c8cc6a8f@xxxxxxxxxxxxxx>

William,

Twenty "No Domain" Properties. The examples generally reflect the class of the subject, i.e. the domain of the property. (For example, is a kind of suggests the triple's subject is of class Kind; and is the datatype of suggest the triple's subject is of class Datatype; andis a role in suggests it's of class Role; and so on). This "is a X of" is not more informative than just

(X)  of  Something   where (X) is an instance of class X

Implied is these properties are each without domain. However I wonder about many eg is a datatype for, a property which likely is of domain Datatype; and plays the role in, of domain Role), implication being the class of the subject is implicit per the property's name; isn't this under-specification? Is it true, for instance, that every conceivable resource plays the role in some-thing either as an actor, a function or otherwise?

Your goal for properties "devoid of domain specific content" defaults the range of all these properties to rdf:Resource. Cannot the model be more specific, relating actors roles events? I once wrote about the basic model of interest being one representing staged performances, including others like script and scene. "devoid of domain specific content" sounds underspecified to me as above.

I agree with the goal though, to have the range and domain of a property be unbounded. If properties are, say, prepositions & verbs, then they must be without range or domain. Logically the RDF Model suggests doing exactly this, as it defines the term Statement composed of Subject Predicate Object, a very grammatical model. Notionally "predicates" decompose to predicate-verb and -object, the latter being a Clause -- a subtype of Statement. Thus properties are named only as verbs & prepositions.

Tenseless Amodal Properties. I'd like to know how you'd model this in RDF triples then

past(Harry believes (John Know Bill))

I know for me it'd be:

Person:Harry had [[Belief:That JohnKnowsBill]]
Belief:ThatJohnKnowsBill of [[Type:Belief]]
Belief:ThatJohnKnowsBill of [[Type:Clause]]
Belief:ThatJohnKnowsBill subject [[Person:John]]
Belief:ThatJohnKnowsBill predicate [[Property:foaf:knows]]
Belief:ThatJohnKnowsBill object [[Person:Bill]]

I think that in an ontological language,  the individual english words are not separate, but part of a
singe meaning, such as 'there exists', and 'for all', and 'if... then'.  These just happen to require two words in English.

I think the goals of computational ontologies are to parse model & mine (shake rattle & roll!) those words!

Thanks - jmc


On 19.05.2013 15:58, William Frank wrote:

I left out a few key ones:

is a template for

is a specification of

is in the domain of

is the controller for the domain of




On Sun, May 19, 2013 at 6:50 PM, William Frank <williamf.frank@xxxxxxxxx> wrote:


On Sun, May 19, 2013 at 5:17 PM, <jmcclure@xxxxxxxxxxxxxx> wrote:

My issues with relations named like "is-part-of" are


This is interesting, in that the ONLY relationships I would like to see are of this kind,though 'is-part-of' is the most problematical.  So, we have made totally oposite conclusions, based on our mutual decades of practice and study.   What does this mean, I wonder. 

I have found  that the cleanest way to build an ontology is to severely restrict the relationships names, to those that are devoid of domain specific content, using only fifteen, To whit:

is a kind of
is a part of
is a role in
plays the role of in
is an instance of
is a life cycle state of
is a descriptor that applies to
is a data value for the descriptor D
is the data type of
is an actor in
is a policy of an actor in
is a resource used by
is a goal of
is an action of (as many arguments as represent things involved)


  • the concept of "part" cannot be qualified without resorting to sub-properties
  • the instance of the property itself cannot be qualified, period

Interested to hear what these mean. 
  • multiple tenses (was-part-of, will-be-part-of, might-be-part-of) balloon all ontologies
I have never heard this view before.  What I have always heard, and firmly believe, after decades, is that the essense of an assertion is a proposition that is tenseless and modal less.

so that (John know Bill) shows a picture of the world, and we can modify the proposition with a tense

past(John know Bill)

now (John know Bill)

or modify it with various modalities:

deontic modalities

must (John know Bill)

may not (John know Bill)

epistemic modalities

Harry believes (John Know Bill)


etc. 



  • the operative term "of" presents itself as a lexical afterthought

I think that in an ontological language,  the individual english words are not separate, but part of a singe meaning, such as 'there exists', and 'for all', and 'if... then'.  These just happen to require two words in English.
 

This is only one example. I can think of many others all conforming to verb-noun-preposition used to name a relation between entities (eg is-employed-by).


This would be something many would model as follows.

 

The impact a property-name exerts across the spectrum -- during input, storage, queries, exchange, etc. -- is one with real-life practical (read, expensive) consequences. Growth becomes unsustainable.

The most widely understood discriminator between "non-semantic" systems and "semantic" systems is that properties are named differently: in "old style" systems these names are nouns, perhaps qualified nouns; in "new style" systems these names are, uh, something other than a noun.

Consequently ontologies I see are near-doubled in size: they have both a class and a property named X, as "old style" names promulgate into "new style" systems.

I argue the industry badly needs consensus about the best practice for how attributes/relations are to be named. It affects EVERYTHING. Ontolog is the only forum I've found appropriate to this question. It really needs to be addressed - so much else is, imho, just a sideshow for all those focused on practical applications of semantic technologies.

Thanks - jmc


 

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