[Top] [All Lists]

Re: [ontolog-forum] using SKOS for controlled values for controlled voca

To: ontolog-forum@xxxxxxxxxxxxxxxx
From: Mike Bergman <mike@xxxxxxxxxxxxx>
Date: Tue, 12 Oct 2010 11:49:17 -0500
Message-id: <4CB4918D.8090408@xxxxxxxxxxxxx>
Hi Ed,    (01)

Beautifully lucid, as always.    (02)

Mike    (03)

On 10/12/2010 11:19 AM, Ed Barkmeyer wrote:
> Whilst not claiming to the education that you all clearly possess in
> this area, I would like to support John's position, if in a curious
> way.  I do not believe that many textbooks are written in natural
> language, and I am not convinced that many formal documents -- treaties,
> contracts, political positions, etc. -- are written in 'natural language'.
> It seems to be a human trait, or at least a European one, to create very
> formal languages that resemble natural language, but have purely
> technical vocabularies, and carefully chosen turns of phrase that are
> themselves technical in meaning.  Yes, these writings follow the natural
> language grammar, but tools that support the truly 'natural' language,
> like WordNet, are nearly useless in determining the semantics of the
> utterances.
> In short, many of the corpora that we are now trying to interpret
> automatically are written in controlled languages, with some natural
> language properties.  And it seems to me that the primary use of SKOS is
> to capture the fixed terminology of such languages.  But SKOS lacks the
> ability to deal with juxtapositions and turns of phrase, which are
> common parts of the means of conveying the semantic load ("context", if
> you must) in these controlled languages.
> Conversely, it has been my experience that almost all ontologies are
> subjective, which is to say, they represent the objective world as seen
> through a particular lens.  In that way, they have all of the properties
> of a semantic corpus that we assume for a natural language text, and
> document with some kind of "metadata" -- author, date, etc.  But whereas
> a natural language text can betray its viewpoint internally, by choice
> of terms and positional linkages, ontologies explicitly assume that a
> term means its formal definition and nothing more.  So, as Leo says,
> there is a continuum here, and it is probably better to think of it as a
> multidimensional surface than a 2D curve.  Every point in that continuum
> has some value in capturing and conveying knowledge, but the values may
> be of different kinds.
> The problem of classification of these points (a la Linnaeus) is to
> carefully define the specific observable traits that are necessary and
> sufficient conditions for membership in a category.  The best we can say
> for ontologies is that they are written in controlled languages that
> have a formal mathematical semantics, full stop.  That definition is
> very clear.  Whether it says anything of real value about the knowledge
> conveyed is 'quite another thing entirely'.  It says nothing whatever
> about their 'semantics' in the linguistic sense, or their 'viewpoint',
> etc.  Ontologies are yet another form of conveying knowledge, that has
> both the advantages and the limitations of technical support.
> -Ed
> John F. Sowa wrote:
>> Patrick, Graeme, Leo, Simon,
>> There are two totally different ways of using logic + ontology:
>>    1. Artificial mathematical systems:  Developing a system of formal
>>       logic and using it to define some kind of artificial system, over
>>       which we have total control.  An example would be some system of
>>       pure mathematics for which we have no applications in mind.
>>       Another example would be a some data structures inside a digital
>>       computer.
>>    2. NL semantics:  Describing some subject that people talk about
>>       in some natural language.  This includes every branch of science,
>>       engineering, medicine, business, politics, and the arts.
>> For anything in #2, the entities described by the ontology must
>> be related directly or indirectly to whatever people who use the
>> terminology refer to.  You can't claim that one notation (say SKOS)
>> deals with terminology and another one (say OWL) deals with ontology.
>> If they are using the same character strings for the same subject
>> matter, there is no difference.
>> PD:
>>> Graeme has another observation about language that may be of interest:
>> GH:
>>> This seems to arise from a combination of overenthusiasm for Western 
>scientific method
>>> and a misunderstanding of the nature of language that borders on fear. In 
>this view, language
>>> is a messy and highly imperfect medium that is not to be trusted, but 
>rather must either be
>>> sidestepped entirely or be beaten into submission by means of logic and 
>> LO:
>>> This seems like an anti-science and anti-logic quotation, I hope out of 
>>> It seems it is hard to be a computer scientist or engineer if you don't 
>>> in science and logic.
>> I think that Leo doesn't get the point that Graeme is trying to make.
>> My interpretation of Graeme's comment is that certain logicians, such
>> as Frege, Russell, Carnap, and Montague, were hopelessly misguided
>> about the nature of language and its relationship to logic.
>> I completely agree with that interpretation.  My three favorite
>> philosophers are Peirce, Whitehead, and Wittgenstein.  As logicians,
>> they were just as brilliant as the four above.  But they also had
>> a much deeper and more realistic understanding of the nature of
>> language and its relationship to the world and to the people who
>> use it to talk about the world.
>> In my paper "The Role of Logic and Ontology in Language and Reasoning",
>> I make the point that it is disastrously misleading to claim that the
>> semantics of NLs is *based on* logic.  Instead, it is more appropriate
>> to say that every version of logic and ontology that anybody has ever
>> proposed has been invented as an *abstraction from* NLs.
>> LO:
>>>   I don't think the answer is to throw our hands up and say
>>> "Oh, language is ineffable, inscrutable!"
>> I completely agree.  Peirce, Whitehead, and Wittgenstein would never
>> say that.  See my paper with quotations from them.
>> SS:
>>> Controlled Vocabularies are Controlled, in the same way that Controlled
>>> Natural Languages are Controlled...
>>> However, the constraints that are placed on the Terms permitted/the subset
>>> of syntax recognized require a certain degree of training before new terms
>>> can be added, or new sentences written.
>> I have been advocating CNLs for years. You can use CNL terms in
>> an abstract way when you're defining an artificial mathematical
>> system (point #1 above).  But when you're using logic plus ontology
>> for #2 (anything in the real world), the controlled vocabulary is
>> nothing more nor less than the labels for your ontology.  And it is
>> also a subset of the same terms that are commonly used in the field.
>> Some of the unused senses for each term might be disallowed in a CNL,
>> but people routinely do that with any NL.
>> SS:
>>> The important thing to remember is the KOS Concepts are essentially
>>> intentional-with-a-t.
>> You're making a distinction between prescriptive (intentional) vs.
>> descriptive (presumably more objective).  So what?  You can use NLs,
>> CNLs, or ontologies in either way.
>> SS:
>>> Controlled Vocabularies that allow Hierarchical relations must
>>> follow other constraints: the most important one is that the
>>> relationship must always be true. That means that if Term A has
>>> Broader Term B, everything that is about A must necessarily
>>> in some fashion also be about B. [Term == Concept in KOS speak].
>> That's fine.  But note the word 'about'.  That word is not
>> spelled the same as the logicians' word 'denote'.  That
>> indicates that they don't have the same meaning.
>> For example, the term 'paw' denotes a part of an animal,
>> not a type of animal.  But if you talk about a cat's paw,
>> you are talking *about* a cat.
>> The relation 'subtype', which is usually used in ontology,
>> is defined in terms of denotation.  The relation 'narrower',
>> which is commonly used in library science, is defined in
>> terms of aboutness.  Denotation and aboutness are not the
>> same.  Therefore, 'subtype of' and 'narrower than' are
>> not the same.
>> The fact that SKOS uses one term and OWL uses another means nothing.
>> You could introduce 'aboutness' as a primitive into OWL and use it
>> to define narrower-than.
>> LO:
>>> Of course there is a continuum working here, as is usual, but there
>>> can be discrete points in that continuum, which act as clarifying
>>> spikes or way-stations...
>> I certainly agree.  But the level of precision that is possible with
>> any subject depends on the application.  SKOS is more often used
>> with applications for which people make less sharp distinctions.
>> If you use OWL for the same subject, you can't make it any more
>> precise than you can with SKOS.
>> LO:
>>> there are typically clear differences between controlled vocabularies
>>> and thesauri, on the one hand, and ontologies, on the other.
>> No.  Look at medicine, for example, there is a one-to-one mapping
>> from the terminologies used by the physicians to the ontologies.
>> Patients, however, don't know the more precise terms.  So they
>> use vaguer words, and they don't observe the constraints.
>> LO:
>>> "Narrower than" is not the same as "Subclass of"
>> Of course not.  They are spelled with different character strings.
>> That indicates that they are different.  Note my comment to Simon.
>> So far, you have not given a single reason why SKOS can't be
>> considered anything but a subset of OWL with a different choice
>> of metalevel terms.
>> John
>> _________________________________________________________________
>> Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/
>> Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/
>> Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
>> Shared Files: http://ontolog.cim3.net/file/
>> Community Wiki: http://ontolog.cim3.net/wiki/
>> To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
>> To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx
>    (04)

Message Archives: http://ontolog.cim3.net/forum/ontolog-forum/  
Config Subscr: http://ontolog.cim3.net/mailman/listinfo/ontolog-forum/  
Unsubscribe: mailto:ontolog-forum-leave@xxxxxxxxxxxxxxxx
Shared Files: http://ontolog.cim3.net/file/
Community Wiki: http://ontolog.cim3.net/wiki/ 
To join: http://ontolog.cim3.net/cgi-bin/wiki.pl?WikiHomePage#nid1J
To Post: mailto:ontolog-forum@xxxxxxxxxxxxxxxx    (05)

<Prev in Thread] Current Thread [Next in Thread>