Re: discussion about meaning and senses

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 is the case? 

Regards, 

Guido Vetere
Manager, Center for Advanced Studies IBM Italia
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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



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