Re: discussion about meaning and senses

Guido (and Wim, see below), all,

  ok, I see your point now.

Actually, I fully agree with this view; it also corresponds to the one 
we have adopted in the lemon model. So yes, I would also advocate a view 
of senses as distinct objects which reify the relation between 
expressions and references, either to classes of objects or single 
objects (or possibly also intensions, tbd).

As a side comment, it seems that you have clearly a "realist" view on 
ontologies, while I would not see any problem in saying that the concept 
of a "squared circle" exists (after all people have tried to construct 
it ;-), but it could be argued to have an empty extension, at least from 
a realist's point of view ;-) Anyway, that is not something that I want 
to elaborate and discuss much further.

In any case, I think we should be rather agnostic to which type of 
ontology we are assuming, i.e. whether it is a "realist" ontology, a 
cognitively or a linguistically-oriented ontology. We should also be 
agnostic with respect to the degree of axiomatization.

I think we should try to agree on the following: there are *o*ntologies 
out there modelling different domains, adopting different perspectives 
and with varying degrees of rigor, axiomatization etc. Some concepts 
modelled in these *o*ntologies correspond to concepts that a "realist" 
would regard as valid concepts, some other do not. Some concepts might 
exist in the "mind" of speakers of a particular language, others might 
be more universal. This is in line with Wim's reference to the LOD where 
we currently find this heterogeneity.

So I think the question we should be pursuing in this group is: given a 
particular resource out there in the LOD, e.g. DPedia, some other 
ontology or dataset, how do we capture or express the ontological 
commitment of words with respect to a given LOD resource or LOD vocabulary?

And I agree that we should not conflate linguistic senses (as reifying 
objects in a semiotic triangle) with (ontological) resources or 
concepts, but as Wim rightfully says, I think the main challenge is 
capturing what we could call the "mapping" between "linguistic signs" 
and "ontological signs".

The meaning of a "linguistic sign" is expressed by some sense that can 
be quite hard to formalize. The sense can in turn be approximated by an 
"ontological sign" the meaning of which can be more or less axiomatized.

So, assume we have an ontology about people where we define a concept 
Bald = HasNoHair

Clearly, as we have argued, it would be wrong to say that the word 
"bald" has the meaning of concept "Bald" in our ontology.
However, I think it would be legitimate to claim that the the word 
"bald" can be used to refer to a member of the extension of the concept 
"Bald".
This is clearly different from saying that the concept Bald represents 
the meaning of the word "bald".

So what I am proposing is that the semiotic triangle we consider looks 
as follows:

Expression (in some language)  --> can be used to refer to element in 
the extension of --> Concept

where the connection between the Expression and the Concept is reified 
by some "Sense Object". We have discussed previously why this "sense 
object" is needed and I will not repeat the thread here.


So I think we should be concerned with spelling out this "can be used to 
refer to" and define ways in which this mapping can be specified (along 
the lines of Wim's proposal).

Best regards,

Philipp.




Am 24.08.12 18:01, schrieb Guido Vetere:
> Philipp,
>
> thank you, I enjoy this discussion very much too, hope that continuing 
> it some more can be useful for our work.
>
> I'm pretty sure that, normally, there are ontological commitments in 
> our words, the problem is that it is not always clear what kind of 
> commitments they are, and whether you can take for granted that 
> linguistic agents always share the very same set of commitments. For 
> this reason, many philosophers have argued that natural language is 
> (let's say) 'ontologically opaque' (see W.V.O.Quine, Ontological 
> Relativity and Other Essays, 1969). So, I think that either we embrace 
> a sort of 'naive realism' by claiming that, on the contrary, lexical 
> senses convey clear, shared and transparent ontological commitments 
> (i.e. if I say 'bald' then there are plainly 'bald things'), or we 
> should keep lexical senses carefully separated from (and yet somehow 
> related to) the kind of ontological distinctions a linguist wants to 
> adopt, which is what Senso Comune advocates and implements.
>
> Note that nothing prevents ontological categories to match linguistic 
> senses (in fact, this is quite common), but this cannot be the rule, 
> since there are ontological distinctions which are not necessarily 
> captured in ordinary languages, e.g. 'abstract' vs. 
> 'non-spatio-temporal-particular' in DOLCE. On the other hand, if you 
> push everything you can say into an ontology, you could end up 
> accepting the reality of 'square circles' much as Meinong did. This 
> should suffice, in my view, for opting in favour of a conceptual 
> distinction between linguistic senses and ontological categories. This 
> does not necessarily mean that we should adopt different formal 
> languages for senses and categories respectively, or that is anyhow 
> impossible to mix ontology and lexicon in the very same resource 
> (actually, this is usual in ICT ontologies). It's a completely 
> different question, I think. Modelling a linguistic sense in OWL would 
> not promote it to the status of ontological category more than UML 
> would make the distinction of 'object' from 'event' a software artifact.
>
> It is easy to see that by modelling linguistic senses as a distinct 
> kind of objects, which reify the relation between expressions and 
> references to (classes of) objects of experience or thoughts, one ends 
> up implementing something similar to a 'semiotic triangle', whose 
> vertexes stand for, roughly, Expressions, Senses, and Things. 
> Ontological categories lead to a (crisp) partitioning of the set of 
> Things that you allow in the logical Universe, while Senses (which may 
> be part of the Universe) can be related the one another (e.g. 
> inclusion, disjunction, relatedness) to model linguistic intuitions. 
> Note that Senses do not require a definite extensional interpretation 
> over the whole Universe.
>
> Hope that this helps and makes sense.
>
> Cheers,
>
> Guido Vetere
> Manager, Center for Advanced Studies IBM Italia
> _________________________________________________
> Rome                                     Trento
> Via Sciangai 53                       Via Sommarive 18
> 00144 Roma, Italy                   38123 Povo in Trento, Italy
> +39 (0)6 59662137                 +39 (0)461 312312
>
> Mobile: +39 3357454658
> _________________________________________________
>
> Philipp Cimiano <cimiano@cit-ec.uni-bielefeld.de> wrote on 24/08/2012 
> 12:04:18:
>
> > Philipp Cimiano <cimiano@cit-ec.uni-bielefeld.de>
> > 24/08/2012 12:04
> >
> > To
> >
> > public-ontolex@w3.org
> >
> > cc
> >
> > Subject
> >
> > Re: discussion about meaning and senses
> >
> > Dear Guido, all,
> >
> >  I am not that sure we need a real distinction between *O*ntology
> > and *o*ntology. I think that this distinction has been emphasized 
> too much.
> >
> > With the big *O* I refer to what you call an ontology in the
> > philosophical sense as a theory of what exists in reality.
> >
> > With a small *o* I refer to the formalization of the meanings of
> > concepts in some logical theory with respect to some language (be it
> > first-order, fuzzy logic, modal logic, OWL, DL, you name it).
> >
> > Honestly, for me there is not much of a difference, for the 
> following reasons:
> >
> > 1) There is  *O*ntology in every *o*ntology. When writing down a
> > logical theory (*o*ntology), one has to think about what type of
> > things exist in reality (*O*ntology) and decide how to model/
> > represent their properties within some formal system. That means,
> > there needs to be some conceptualization (in the sense of Guarino)
> > as well as some ontological commitment of the logical theory.
> >
> > 2) There is also *O*ntology in any lexical resource. Every lexical
> > resource makes choices with respect to the number, granularity etc.
> > of meanings that a lexical entry is supped to have. These are
> > *O*ntological choices essentially.
> >
> > *o*ntologies and lexical resources differ in the formalism
> > (language) they use to describe the meanings of symbols, i.e. some
> > logical language vs. (say) natural language glosses or some atomic
> > markers (in the line of preferential semantics).
> >
> > An *o*ntology can be less or more axiomatized in the sense of
> > reducing the possible models more or less. The more we axiomatize,
> > the more we reduce the models. The more we axiomatize, the more a
> > machine or computer will be able to infer or to verify whether
> > symbols are used in the right way (i.e. according to their
> > ontological commitment). The less we axiomatize, the more we rely on
> > the intuition of people in using these symbols and the less we can
> > check whether the symbols are used properly. This vagueness has
> > clearly advantages in many respects, e.g. for the sake of
> > interoperability where many people can (claim) to refer to the same
> > vague concept ;-) This clearly undermines the idea of
> > interoperability, i.e. we end up "agreeing on the fact that we 
> agreeon sth.".
> >
> > Now clearly, which language and formalism is the best to represent
> > the meaning of concepts (linguistic or non-linguistic, common sense
> > or whatever) is a question that is clearly out of scope of this
> > group and I will not make any statements about how to best express
> > the concept of "baldness"  or any other concept for that matter. How
> > many axioms and which type of axioms would be needed to represent
> > the meaning of baldness  is also something that we should not be
> > particularly concerned with. But I agree with you that the meaning
> > of come concepts can be approximated in some logical language, while
> > others are not formalized that easily (because they are inherently
> > hard to define or because the logical language is not adequate).
> >
> > Thus, for me there is not much of a difference between a concept, a
> > category or a linguistic sense. In all cases we make fundamental
> > *O*ntological choices about what exists and which meanings we wish
> > to distinguish for some purpose. The crucial question is clearly how
> > and to which extent and in which language we can specify and
> > formalize the meaning of a symbol (or word for that matter), a
> > question that is out of the scope of this working group.
> >
> > For the sake of this group, I would propose that we assume that
> > there are already resources that make basic *O*ntological choices,
> > i.e. with respect to number and granularity of meanings as in any
> > lexical resource or with respect to how many and which meaning
> > distinctions are important for a certain domain/application (as done
> > in any *o*ntology).
> >
> > But before going on, I would like to understand a bit more what you
> > mean with "pushing the sign upfront" and what you mean with a
> > "native semiotic kind of modelling".
> >
> > Apologies for the longer response. I hope that this all makes sense 
> (Guido?).
> >
> > And I welcome very much that we discuss these issues further. So
> > thanks for your very valuable input Guido!
> >
> > Regards,
> >
> > Philipp.
> >
> >
> >
> > Am 20.08.12 18:26, schrieb Guido Vetere:
> > Philipp,
> >
> > thanks for your summary. Actually, there may be different visions on
> > fundamental aspects of our work; although we can get along with this
> > in a pragmatic way, I think that is worth discussing them a little
> > bit more, to see if we can get to an agreement, or at least to agree
> > on the nature of our disagreement :-)
> >
> > I think that we have to agree on the meaning of 'ontology', or at
> > least be aware of the polysemy of this term. Whereas philosophers
> > have mostly intended 'ontology' as a theory of what exists in the
> > reality (including 'socially constructed reality') independently of
> > linguistic habits, computer scientists, in general, use 'ontology'
> > to refer to any formalised conceptual schema, whether it contain
> > common sense notions (e.g. 'bald') or metaphysical ones (e.g.
> > 'substance'). Of course, in the latter sense, 'ontology' may be
> > considered as a kind of formal representation of linguistic
> > meanings, hence there is obviously a continuum from lexicons to 
> ontologies.
> >
> > Sorting this continuum based on the 'degree of formalisation', may
> > help in the integration of different onto-lexicons, but it would be
> > quite difficult to find out a criterion to estimate the formality of
> > the representation of a linguistic sense. Pick up 'bald', for
> > instance. How many axioms would you need to formalise this concept?
> > Would a fuzzy logic provide a better formalisation than a typicality
> > logic? Who knows? From a 'normative' perspective, on the other hand,
> > we could tell people how to better organise their onto lexical
> > content on the Web. As you know, we experimented an approach where
> > 'ontology' is taken 'philosophically', hence the issue of
> > distinguishing common sense, linguistic (i.e. mostly vague) concepts
> > from 'metaphysical' categories is taken into account. This is
> > achieved by implementing a semiotic approach, i.e. pushing the
> > 'sign' upfront, much in the line of what Aldo says. Of course, I
> > think that there are benefits in adopting a 'native semiotic' kind
> > of modelling, and we can discuss it, but as a matter of facts most
> > of the (so called) ontologies published on the Web provide a mix of
> > (what we consider as) categories, linguistic senses, whatever.
> >
> > So, if the aim of this group is that of providing guidelines for
> > building new resources or restructuring existing ones, then we
> > should reach an agreement on whether there is a distinction between
> > ontological categories and linguistic senses. If, on the contrary,
> > we focus on integrating existing resources and practices, then we
> > must assume that such a distinction is just irrelevant. Which one 
> isthe case?
> >
> > Regards,
> >
> > Guido Vetere
> > Manager, Center for Advanced Studies IBM Italia
> > _________________________________________________
> > Rome                                     Trento
> > Via Sciangai 53                       Via Sommarive 18
> > 00144 Roma, Italy                   38123 Povo in Trento, Italy
> > +39 06 59662137                     +39 0461 314031
> >
> > Mobile: +39 3357454658
> > _________________________________________________
> >
> > Philipp Cimiano <cimiano@cit-ec.uni-bielefeld.de> wrote on 14/08/
> > 2012 08:59:59:
> >
> > > Philipp Cimiano <cimiano@cit-ec.uni-bielefeld.de>
> > > 14/08/2012 08:59
> > >
> > > To
> > >
> > > "public-ontolex@w3.org" <public-ontolex@w3.org>
> > >
> > > cc
> > >
> > > Subject
> > >
> > > Re: discussion about meaning and senses
> > >
> > > Dear Guido, Aldo, Piek
> >
> > > I have been following the discussion in silence so far as I have
> > > been traveling and not found the time to summarize the current state
> > > of the discussion.
> > >
> > > First of all, apologies for my misconception of what bald means ;-)
> > >
> > > But aisde from this misconception, my main point actually was that I
> > > do not think that we need to strictly separate the ontological from
> > > the 'ideal' or 'linguistic' meaning as Guido is advocating.
> > > In fact, I like the point raised by Aldo that we could see lexicons
> > > and ontologies not as opposites but rather as points along
> > > a continuum where there can be more or less formalization (I hope I
> > > got Aldo right, did I?)
> > > So this means that meanings can be highly formalized or not
> > > formalized at all. "Bald" would be a very vague concept along these
> > > lines which would be possibly not axiomatized at all other than
> > > saying sth. like $\forall x Bald(x) \rightarrow Human(x)$ which is
> > > more or less
> > > what in Senso Comune is expressed by the "characterizes Humans".
> > > So I like the perspective that in principle we *can* formalize any
> > > aspect of the meaning of words, but for pragmatic reasons we might
> > > decide not to do it (because the effort is too high and it does not
> > > pay off / the inferences we could draw and not particularly
> > > interesting for applications, etc. or there is no agreement on how
> > > to formalized). These are all pragmatic reasons, but no principled
> > > ones again the formalization of the meaning of some lexical element.
> >
> > > So let me try to summarize the state of play of the discussion:
> >
> > > Guido (1): we clearly need senses as reified objects, reifying the
> > > association between lexical entries and concepts.
> > > This is necessary because we need to predicate over these
> > > associations. For instance, many 'senses' come with specific
> > > grammatical constraints, e.g. for nouns, plural is often used to
> > > mean something different from a mere collection of individuals, as
> > > in Italian 'acqua' (water) and 'acque' (thermal treatments).
> > > => I fully agree with this and in fact such a reification is at the
> > > core of our lemon model for the same reasons as mentioned by Guido.
> >
> > > Guido (2): Linguistic and ontological meanings should be clearly
> > > distinguished. In Senso Comune 'meanings' are regarded in most cases
> > > as vague and idealized meanings that are not properly formalized, so
> > > that interpretation is subjective and can vary depending on the 
> context.
> > > => I would not agree with this point and rather adhere to the
> > > continuum views that Aldo has been putting forth.
> > > The consequence of such a view is that there is in principle no
> > > problem with what Aldo has called "the direct mapping" approach that
> > > I was advocating.
> >
> > > Aldo (1): we should see lexicons and ontologies rather as a
> > > continuum than as an opposition. If possible, and for the sake of
> > > semantic interoperability and reasonability, concepts should be
> > > axiomatized as far as possible, but if for pragmatic reasons such as
> > > formalization is not provided, then a semi-formal definition as
> > > provided in a lexicon (e.g. through a gloss or lexical
> > > relationships) is better than nothing. In the long-term, such
> > > "informal" meanings might be incorporated into the ontology by
> > > axiomatizing them appropriately.
> > > => I share this view.
> >
> > > Piek (1): was posing the question of whether there is any
> > > fundamental line between what should be formalized and what not.
> > > Clearly, I do not have a definite answer to this, but all those
> > > lexical and linguistic properties that Piek mentions (morphology,
> > > pronunciation, lexical relations) etc. should be definitely
> > > modelled/represented at the lexical side (e.g. in OWL, which does
> > > not mean that they are axiomatized along the lines of the argument
> > > above). In this sense I do indeed advocate the two modular layers: a
> > > lexical and a semantic/ontological one. Of course, the crucial
> > > question is whether we have to model the semantic implications of
> > > certain linguistic properties/distinctions. Take the word "dog" and
> > > its plural "dogs". Clearly, they have different semantics, as "dog"
> > > is used to refer to one element in the set of dogs, while "dogs" is
> > > used to refer to a set of at least two elements in the set of dogs.
> > > However, this is purely linguistic knowledge that is "systematic" in
> > > the sense that it holds for all nouns. As such, it is questionable
> > > whether this should be modelled in the lexicon-ontology interface.
> > > But I agree that the interesting question is which aspects of the
> > > meaning of lexical entries that touch the actual interface should be
> > > formalized and how (one example is register).
> >
> > > By the way: both layers can support reasoning, but in a different
> > > domain. In one layer, we reason about linguistic properties, while
> > > in the ontological layer we would reason about (domain) concepts.
> > >
> > > So there are certain properties in the list of Piek that are purely
> > > linguistic and do not touch the meaning layer at all (e.g
> > > morphology, pronunciation, etc). while there are others that
> > > modulate the meaning. The latter ones are the ones we should take
> > > about in more detail.
> > > In any case, I think it would be worth going through the bullet list
> > > of Piek in our next telco to reach some consensus there.
> >
> > > Just my two cents for now.
> > >
> > > Best regards,
> > > Philipp.
> > > --
> > > Prof. Dr. Philipp Cimiano
> > > Semantic Computing Group
> > > Excellence Cluster - Cognitive Interaction Technology (CITEC)
> > > University of Bielefeld
> > >
> > > Phone: +49 521 106 12249
> > > Fax: +49 521 106 12412
> > > Mail: cimiano@cit-ec.uni-bielefeld.de
> > >
> > > Room H-127
> > > Morgenbreede 39
> > > 33615 Bielefeld
> >
> >
> >
> > IBM Italia S.p.A.
> > Sede Legale: Circonvallazione Idroscalo - 20090 Segrate (MI)
> > Cap. Soc. euro 347.256.998,80
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> > International Business Machines Corporation
> >
> > (Salvo che sia diversamente indicato sopra / Unless stated otherwise 
> above)
> >
>
> > --
> > Prof. Dr. Philipp Cimiano
> > Semantic Computing Group
> > Excellence Cluster - Cognitive Interaction Technology (CITEC)
> > University of Bielefeld
> >
> > Phone: +49 521 106 12249
> > Fax: +49 521 106 12412
> > Mail: cimiano@cit-ec.uni-bielefeld.de
> >
> > Room H-127
> > Morgenbreede 39
> > 33615 Bielefeld
> IBM Italia S.p.A.
> Sede Legale: Circonvallazione Idroscalo - 20090 Segrate (MI)
> Cap. Soc. euro 347.256.998,80
> C. F. e Reg. Imprese MI 01442240030 - Partita IVA 10914660153
> Società con unico azionista
> Società soggetta all'attività di direzione e coordinamento di 
> International Business Machines Corporation
>
> (Salvo che sia diversamente indicato sopra / Unless stated otherwise 
> above) 


-- 
Prof. Dr. Philipp Cimiano
Semantic Computing Group
Excellence Cluster - Cognitive Interaction Technology (CITEC)
University of Bielefeld

Phone: +49 521 106 12249
Fax: +49 521 106 12412
Mail: cimiano@cit-ec.uni-bielefeld.de

Room H-127
Morgenbreede 39
33615 Bielefeld