RE: WordNet modelling in Lemon and SKOS

Dear John, all,

 

thanks a lot for the useful resuming schemes in attachment to your email. However, what I notice is that, though potentially reducible, the original emails were that long because of necessary clarifications which are lost in the schemes. So, even what may seem similar from the scheme, is not, and what may seem different, can be rejoint with proper discussion. Much of the issues in discussing these things, derive from the terminology which, while still being assessed, needs to be explicitly clarified when used in each model: you will see in my resume, that I still maintain that my notion of  “sense” (in line with WordNet) does not deserve more, while I agree with your observations: how is it possible? it is simply because we are talking about two different objects, and the contrast is elsewhere.

 

Given that, I much welcome your request for reaching some compact comparison of the proposals, thus I’ll write tomorrow a resume of the model on the wiki, and then maybe we may send shorter emails :-)

In the meanwhile, let me come once more on the discussion here, as I think we are almost close, plus progressive replies are not easily representable in a wiki.

 

I will start with a few notes on adjusting a part of these schemes you drew (I would have done it myself to save your time, but this is an image) for a better comparison, and then try to clarify again on the WordNet modelling issue.

 

1.       Problably an oversight, but the sense arrow in my model is wrong: it is from lexical entry to lexica concept, and not to Ontology Entity. In fact, the Sense class stands in the middle of prop sense’s range and domain, to reify this relation.

2.       One thing which may not be clear from the sole schemes: using solely the class used in each box, can lead to ambiguity, in particular in those cases where the same class (e.g. skos:Concept) could appear in more boxes with different roles in our model (see point 4 below)

a.       A solution is we could mark boxes with two elements: the class suggested (either defined in ontolex or pre-existing) and its role in the ontolex model (later described through accompanying definitions). One example of a role is the “ontoelements” I mentioned in my past email (which can be resources of an owl ontology or skos:concepts as well)

b.      Other solution is we just provide examples (where the thing to model is the same across the three proposals)

c.       A combo of the above

3.       Following your sentence: When defining lemon, we tried to be partly agnostic about the format of the ontology... we assumed it would be OWL, but didn't rule out the case of linking to F-Logic, FOL, etc. >From this point-of-view it is not unreasonable  to consider linking to a SKOS concept hierarchy as an informal ontology.

a.       Yes, I agree. In my email in fact, I used the slightly abused notation ontoelements (just following the “onto” part of the “ontolex” compound), specifying that these ontoelements do not need to be resources of an owl:ontology, and can be skos:concepts as well. A simple operational definition for ontoelements is that they are “elements from the target scheme which we want to linguistically enrich”. The fact that *also* the linguistic resources (thus on the “lex” side) may be represented through SKOS is orthogonal. In this sense, maybe the double reference arrow in the first scheme (lemon-SKOS-OWL model) hints at a different modelling from the other two, while actually it shouldn’t be the case. At least in my case, it is identical to the first one. Btw, to avoid confusion with multiple boxes, I would suggest actually to change, for all the three schemes, to one single box, and write inside it, as a role, something to denote what-I-called-ontoelements (with no specific class, as these can be individuals, properties, classes, skos:concepts)

4.       The skos:it modelling: In my proposal, I want to stress the use of lexical resources properly in the “lex” part of the “ontolex” compound. skos:it (or other solutions) maybe ok for linking generic skos concepts to owl resources, but this is orthogonal with the way I would fit the use of lexical resources (which, by accident, we may model through specifications of SKOS) over our pattern.

 

Concluding, look now at the correct version of my proposal (it is attached)

We have the LexicalEntry-LexicalConcept-OntologyEntity triad which very very closely reminds the LexicalEntry-LexicalSense-OntologyEntity of the lemon model. Ad in effect (modulo the terminological choice of LexicalSense/LexicalConcept), they actually match when used by putting bnodes in place of the element-in-the-middle. In fact, the discussion originated on how I see the use of WordNet, which, to me, contains a conceptual error in the perception of LexicalSense (see later).

And now you also see why I say that my ontolex:Sense does not deserve more than just being a reification. It’s because the important thing that you call LexicalSense (and which, in your opinion, should not be underestimated) is actually what I (following Miller’s paper) call LexicalConcept. Thus I agree with you on its importance and proper characterization, but it has nothing to do with my concept of Sense. 

I originally criticized the use of the word LexicalSense, as to me sense was better to be seen as a relation, than to represent a unit of meaning, and in fact now I’m advocating LexicalConcept (used in WordNet terminology as a general expression for what they called Synset), but at that time, I didn’t insist on it as we were just assessing the model.

However (in my very humble opinion), I see now that the terminological choice of LexicalSense has probably mislead the mapping of WordNet currently in the wiki. Because you modelled senses in wordnet to your LexicalSense, while (if I’m right in interpreting LexicalSense) they are a totally different thing. Senses in WordNet are merely a reification of the word/synset pair, in that when we say that a word has a given sense, it is actually linked to a synset, which (WordNet guys’ word) is something “hinting” at the existence of a concept.

That’s way I said that, whatever we call them LexicalSenses or LexicalConcepts, it’s this entity that should hold synsets, while wordnet senses should be modelled according to my ontolex:Sense class. 

 

Thus, to resume, I repeat here my previous email: in the end, my proposal (still modulo the terminological choice of LexicalEntry/Concept and the addition of Sense) is the same as the original lemon one (and it is used the same way!), but it is the mapping to WordNet I’m mostly criticizing. My one is (IMHO) more representing properly wordnet in the theory, and also (but it is not an accident!) allows to put WordNet synsets, which are still objects of a theory of language, in the proper lex part of the model, and not in the onto one (see the splitting in my drawing).

 

Just a word about the “Meaning” class and the semiotics-owl based Model. I have to read deeply all the emails in that thread, however, I think it more or less coincides with the two other ones (my correct version here), but adds the Meaning concept. It’s not a case that I too used the word Unit of Meaning in the same box with Lexical Concepts. In WordNet theory, they say that a LexicalConcept (a synset) “hints” to the existence of a concept, which is not (however) explicit (, “…synonym sets (synsets) do not explain what the concepts are; they merely signify that the concepts exist”. [1] ).

We can decide to have this “Meaning” explicit in our model (as we know, our model will include WordNet, and have more), but I think it’s not a case that it was dropped in WordNet: it is just the non-representable thing hinted by the Lexical(ized) Concepts. You may have a theory telling you that a certain thing exists, but if it cannot be represented, then a representation model should probably not include it (unless the theory itself is the object of your model). To me, it is better to leave it implicitly “hinted” in the LexicalConcept class.

 

Best,

 

Armando

 

P.S: if we commit to some standard source format for drawing schemes, we can exchange directly the sources on the mailing list/attach them to the wiki. I use Visio which is not right the most open standard, so I’m open to suggestions in case. For now, I’ve edited a completely new one for my model, with the corrections above. 

 

[1] Introduction to WordNet: An On-line Lexical Database George A. Miller, Richard Beckwith, Christiane Fellbaum, Derek Gross, and Katherine Miller


http://wordnetcode.princeton.edu/5papers.pdf

 

 

 

From: johnmccrae@gmail.com [mailto:johnmccrae@gmail.com] On Behalf Of John McCrae
Sent: giovedì 18 aprile 2013 16.43
To: Armando Stellato
Cc: Philipp Cimiano; public-ontolex
Subject: Re: WordNet modelling in Lemon and SKOS

 

Hi Armando, all,

 

I will try to synthesize a few other emails into this reply.

 

Firstly, I agree with much of what of Armando says. Although lexical senses may be a reification of the <Word,Synset> combo as Armando says, I feel this understates the importance of their role. In fact, from my understanding lexical senses constitute an extension of words used with a given meaning, by the same logic that a lexical entry (lexeme) consists of an extension of words used in various inflected form. By the converse it could be argued that the lexeme is therefore just a reification of the <Form,Concept> pair (in fact this approximately what a SKOS-XL label is). The key aspect is that is it useful in at least a significant percentage of language resources, in this case, the use of lexical sense as the annotation point for contexts (register, geographical usage), conditions (lexical selection restrictions) and examples (as in WordNet, see screenshot), make it IMHO a clearly vital part of the model.

 

When defining lemon, we tried to be partly agnostic about the format of the ontology... we assumed it would be OWL, but didn't rule out the case of linking to F-Logic, FOL, etc. From this point-of-view it is not unreasonable  to consider linking to a SKOS concept hierarchy as an informal ontology.

 

Much of the issue in this thread concerns what happens if we then want to link this synset/concept hierarchy to a (formal) ontology. In the following document they propose two options:

 

http://www.w3.org/2006/07/SWD/SKOS/skos-and-owl/master.html

 

They propose "overlay" and "transform" options. I suspect most members of this list would reject the overlay option, so looking at the transform option we see a model using lemon, OWL and SKOS (first part of attached image), which uses the (unfortunately) hypothetical skos:it property to link between the concept (synset) and the ontology entity.

 

In a previous email today I proposed a modelling based on Aldo's semiotics.owl ontology (based on the understanding the lexical senses are expressions, synsets are meaning and ontology entities are references). As we can see this is structurally identical.

 

Finally, I also looked at Armando's proposal, and it also seems very similar in structure. From my opinion it should be possible to move the domain of Armando's sense link to the Sense class* and this would leave us agreeing in the structure if not the names of the labels!

 

Regards,

John

 

* Of course, if we take into account Philipp's proposed shortcut link (see http://www.w3.org/community/ontolex/wiki/Specification_of_Requirements/Lexicon-Ontology-Mapping) between Lexical Entries and Ontology Entites, then this link would simply be the shortcut.

 

On Wed, Apr 17, 2013 at 9:28 PM, Armando Stellato <stellato@info.uniroma2.it <mailto:stellato@info.uniroma2.it> > wrote:

Hi again,

 

First of all,  this is a reply to all three emails from Philipp, John and Aldo (plus something more from other emails). Since the topic is the same, I wrote one single reply, as there are parts of their email in common. Also, a small legenda, for being shorter later in the argumentation:

 

Ontoelement(s): those elements of an ontology which need to be referenced through lexical information, that is, the objects of triples with ontolex:reference as their predicate. Note here that there is some abuse of notation: this “target ontology” could actually be a skos concept scheme and not an owl:ontology. We do not assign any Class here, as these element could be properties, individuals, classes or concepts

3-entity-pattern: that LexicalEntry -> LexicalSense -> OntoElement structure we (more or less) agreed on.

 

Ah, one note…this is not only an interminably long discussion, I propose a model at the end :-D

 

I put here below names of people before any section, so that it is clear who said what and whom I’m replying to:

 

[Philipp]

I agree that in some sense the three-entity path seems an overkill for modelling WordNet. But I think that our goal should be to design a model to works for all cases and not tune the model to the particular case of WordNet. So I would prefer to use the same modelling (i.e. the three-entity path) across all specific resources.

[Armando]

Absolutely agree on our mandate to have something homogeneous and not hard-patched to some specific necessity. My proposed modelling for WordNet is in fact not in the direction of sprouting exceptions from our model to cover WordNet, but is actually (obviously, this is my opinion and I may be wrong) a more trustworthy replication of its structure, which I think is elegantly compatible with our model and even better matches it. Hence more, it fosters a better integration of WordNet when used to enrich an ontology.

However, my perspective is not totally incompatible with some modelling exigencies (see later my reply to John’s observations), and as you will see, some linking can be drawn up.

 

But, to argument better (at least, I hope), I have to take a step back (and sorry, I’ll be going through things that all of you know very well, but still I need to mention them for the argumentation).

 

In WordNet we have words (terms, whatever..), and these words are bound into collections called synonymy sets. To cite the most popular paper [1] about WordNet, “…synonym sets (synsets) do not explain what the concepts are; they merely signify that the concepts exist”. So, ok, synonym sets are just “language extensional hints” to a concepts. We don’t know intensionally what that concept is, but we understand there is and we know linguistically how to refer to it. From a sentence in the same paper, just before the aforementioned one, we read: “The synonym sets, {board, plank} and {board, committee} can serve as unambiguous designators of these two meanings of board”. So, meaning of boards, under an interpretative process, are designated by synsets.

>From the very first rows (the abstract) of that same publication, we read: 

“English nouns, verbs, and adjectives are organized into synonym sets, each representing one underlying lexical concept”.

 

Ok, perfect, personally, I’ve found what I would suggest for that element-in-the-middle in the 3-elements-path. It is called LexicalConcept, and fits dramatically well (even terminologically) as a subclass of skos:Concept. As I said many times, I personally didn’t like LexicalSense as, maybe exactly biased by my knowledge of WordNet, and by a bit of common sense, I would have used the word “sense”, only to represent the relationship which holds between a LexicalEntry and a LexicalConcept. That is to say: a LexicalEntry may have many senses, and each of them is represented through a pointer – through the relation: “ontolex:sense” – to a LexicalConcept, which accidentally in WordNet is a synset (not my words, I’m citing their literature).

 

Thus, recapping, in my view the thing is simple. I try to recap it as Aldo did in his email, but on my modelling perspective; therefore, to me the 3-entities-pattern (and gluing props) in our language would be:

 

Class(ontolex:LexicalEntry) –prop(ontolex:sense)–> Class(ontolex:LexicalConcept) –prop(ontolex:reference)–> An Ontoelement

 

Until now, by purely graph-matching it with what has already been said, it seems I just don’t like the LexicalSense name, and replaced it with LexicalConcept, but there’s something different exactly when we consider a case like WordNet.

Let’s take these two other triples:

 

wordnet:Synset rdfs:subClassOf ontolex:LexicalConcept

wordnet:syn_v_00076153 rdf:type wordnet:Synset

 

thus, here we have just two renamings:

-          a synset instance renaming: very personally, I think the synset code is the most “neutral way” of calling a synset, not biased by one of the terms which are part of it, which always gave me an headache; think this is the same thing Piek was referring to when talking about the choice of word-sensenumber pairs as URIs for synsets in the existing RDF version of WordNet

-          my LexicalConcept class instead of LexicalSense

but, apart from them, I took those two triples exactly as they are from Aldo’s example.

 

Now, the focus of my opposition to the original WordNet example (or better, of some implications of it which I heard as confirmed in the emails), is that I see this class LexicalConcept as exactly the “vague lexical concept” – of which we precisely know a lexical extension – which can be put in between LexicalEntries and ontoelements in the 3-entities-pattern.

It is exactly, for instance, the bnode we put in the example in:  <http://www.w3.org/community/ontolex/wiki/Specification_of_Requirements/Lexicon-Ontology-Mapping#Examples_using_DBpedia> http://www.w3.org/community/ontolex/wiki/Specification_of_Requirements/Lexicon-Ontology-Mapping#Examples_using_DBpedia when we write:

 

:team a ontolex:LexicalEntry ;

  ontolex:canonicalForm [ontolex:writtenRep "team"@en ; ] ;

  ontolex:sense [ontolex:reference <http://dbpedia.org/ontology/team> ;

 

to link the :team LexicalEntry to the dbpedia:team resource.

 

Only…if we are using WordNet, someone has already prepared a set of these LexicalConcepts (seasoned with words!) for us, gave identifiers to them (so no bnodes necessary), and a general class for them, calling it Synset :-)

This is really the central part of what I’m saying.

 

Thus, a very basic (but still compliant) modelling can be:

 

wordnet:syn_n_08225481 ontolex:reference <http://dbpedia.org/ontology/team> ;

 

and we get for free all the LexicalEntries already attached to WordNet, and modelled according to our vocabulary. Obviously, some other work can further enrich the lexical description of a WordNet synset (which in wordnet is just a set of words) thanks to our more fine grained vocabulary allowing for richer characterization of Lexical Entries. Still at least with one row above, we get a lot for free thanks to the mere existence of WordNet.

 

[Philipp]

Assuming that WordNet contains a conceptualization, each synset indeed represents a skos:Concept (a unit of thought) and in that sense it seems reasonable to see a Synset as a reference.

 

[Armando]

Agree on the skos:Concept part, not on the rest. WordNet is a lexical database. Its domain (the set of its linguistic concepts called synsets) is still linguistic, and the concepts of WordNet are thus IMHO these LexicalConcepts I’m advocating. If you commit somehow to WordNet, then you could (you should, in my advice) commit to (and take benefits from) using these synsets as the element-in-the-middle of our 3-entities-pattern.

I’m trying to assess WordNet in the right place of our wider onto-linguistic modelling, and I see it as the linguistic part which needs to be attached to the conceptual part. I wouldn’t like to see WordNet as a domain (world domain) concept scheme with attached labels that can be potentially mapped to our ontoelements. Obviously, the use of skos:Concept may be misleading in its name (as “concept” could induce in the thought that - in the onto-lex composition - it is the “onto” part), but I’m stressing that this extension of skos:Concept should be our ontolex:LexicalConcept, and that this ontolex:LexicalConcept itself is the right cap (superclass) for wordnet:Synset when considering WordNet as a specific instance of a Ontolex-modelable lexical resource. Finally, once more, this implies that Synsets should sit in between LexicalEntries and ontoelements in our 3-Entities-Pattern.

 

I try now to explain the contra for the example currently in the wiki. With the previous modelling, we get almost nothing back: we would have this “general world ontology” called WordNet, which has its lexical entries (mediated through the Sense entity), and we have two distinct universes of possible actions:

1)      we could map the resources of our domain ontology/conceptscheme to the synsets of WordNet, much the same way we map two general domain ontologies or concept schemes.

2)      we could relate specific wordsenses, such as: wordsense-vomit-verb-1, to resources in our ontology.

But pay attention, in what I propose we could link a synset (syn_v_00076153), through ontolex:reference, directly to ontoelements and use it - coherently with our model - to have all of that synsets lexicalentries bound to the intended ontoelement. In the current model instead, by using WordNet senses, we should link each sense of each word to the ontoelements

 

Thus we should state:

wordsense-vomit-verb-1  ontolex:reference    myont:vomit

wordsense-cat-verb-2       ontolex:reference   myont:vomit

 

but…is it not painful? We already had the synset as a common umbrella! Oh yes, surely we could decide some entailment, for which if I link (somehow..how? through skos:exactMatch?) a synset to an element of my ontologies, then all of its related wordsenses (that is, the set of senses for which certain words are bound to that synset) are bound to the ontoelements. But how to state this entailment in the general ontolex vocabulary, since Synsets are out of it? (and in fact the wiki example does not hint at any general definition of wordnet:Synset under some ontolex umbrella, being it only the last resource to be pointed by ontolex:reference, much like an ontoelement from any other ontology).

 

With a slight difference approach from Philipp and John, I see interestingly that Aldo proposed both Synset and WordSense as subclasses of ontolex:LexicalSense. This would mean that Aldo would actually allow to use synsets in the middle of our 3-elements-path

                wordnet:WordSense rdfs:subClassOf ontolex:LexicalSense

                wordnet:Synset rdfs:subClassOf ontolex:LexicalSense

 

this seems discordant from what Philipp and John say. While I obviously agree with the second axiom (it’s basically the core of what I’m saying), personally I can’t see wordnet:WordSense as well as a subclass of ontolex:LexicalSense, and, actually, can’t think how the two things (wordnet:WordSense and wordnet:Synset), which are solidly distinct, can be subclasses of the same class in any possible theory.

 

So (if I’m correct), in the case of Philipp and John, it seems Synset is left away from any convenient reuse, while in the case of Aldo, I’ve this big problem with the double subclassing of both Synset and WordSense under LexicalSense. You may not agree with me, but still it seems something is missing.

I was then trying to do the devil’s advocate and argument against myself: “what if I want to attach a given set of words to one of my ontoelements, but there is no synset in wordnet which rightly embraces it?, that is, for each synset I would consider, there is a word in it that I don’t like“. This could be a good point towards having word senses attached to ontoelements, rather than synsets. But actually it is not, as much as reducing commitment always reduces constraints and problems, but also offers less solutions and opportunities. The paper [1] (and suppose much more literature before that :-D ) is clear on the fact that true synonyms may never exist, and the concept of synonymy is dependent on the context, still the WordNet ontology (as all ontologies do) provides a discretization of a world model, where the “world” is the “generic use of language”, which in most of the cases will work, but may fail where this discretization is not correctly representing a given shade of meaning (i.e. there is no wordnet sense for a word, perfectly fitting the right concept we want to express in our ontology, and thus its lexicalization).
But the truth is always the same in all cases of commitment: you can decide to re-use what you have as much as you like, and get the benefits deriving from the (shareable!) work of others up to a reasonable extent. If nothing in wordnet fits a specific ontoelement of yours, then put a blank node as LexicalConcept in the 3-entity-pattern, and go along in customizing your specific lexical characterization, while still keeping the rest (probably 99% of your ontology) happily WordNet-decorated.

 

To recap until now, the moral behind all of that (beyond triples, names etc…), is that WordNet is a linguistic resource, and by treating it as a generic conceptualization, we could miss the opportunity of using it for what it is.

 

Now, a final remark, because John (and I want to assure here Piek as well about his concerns :-) ) is totally right in his email, when he says: 

[John]

“Firstly, I think an important point here is that WordNet does in fact have senses as a concept distinct from Synsets and Words“. 

 

[Armando]

Surely this is the best argumentation on supporting the fact that these senses shouldn’t go away if we want to fully support WordNet.

By first, something I already expressed in my previous email: it may not be our priority to have all of WordNet inside OntoLex; we could cover 85% of WordNet model through OntoLex, and then have some specific parts of it not under the cap of our generic vocabulary (but still WordNet having its own RDF modeling scheme, 100% covnering wordnet, and 85% mapped to ontolex). I’m not saying we shouldn’t cover it, I just want to stress that the focus in the discussions before is not on covering 100% WordNet, but on how to fit it inside our model, and how to use it to enrich an ontology. Given this, let’s assume that we want to cover it 100% and let’s go ahead. 

 

All of us know that, when representing a domain through a given model, we may have to represent things we perceive as different, through identical constructs. When we are in RDF, sometimes we have to reify relationships into entities. Conversely, in relational modelling, all entities and relations from an ER model become relations (e.g. then tables in a DB). So, surely fact is that in the traditional WordNet index-file-based DB, there is a sense index file, and that there, bindings between Synsets and Words are expressed, because sometimes they need to be cited explicitly as first-class citizens. 

Let us consider the case of lexical relations (which, namely, cover relations between words). In WordNet, (since it was born merely “to be a theory of the Word Meaning box”, [1, pag. 5]) there are no purely lexical relations, and its lexical rels are actually stated between senses of a word, that is between word-synset pairs. For instance, in common speaking, we say that rise/fall are antonyms, but surely we are not addressing the US expression of “autumn” as opposed to “rise”: well, WordNet accounts for that, by specifying that two words are antonyms only when considering some of their intended senses.

Another example is the tag count, again in wordnet, telling how many times a specific word with a particular sense (tagged with a given synset) has appeared in a corpus (e.g. SemCor). Or the sense ordering already mentioned in other emails.

But is it anymore important than just an escamotage for adding additional statistical data, put some ordering, or better qualify lex relations? I think not. Synset and Words are the VIPs. Sense (in wordnet) is just the reification of the <Word, Synset> combo.

 

So, this is the notion of “sense” in WordNet: a glueing object relating a Word to a Unit of Meaning (a lexical concept). The lexical concept is “hinted” by the index (through the synset code) and linguistically expressed by means of a Synset’s lexical extension: its words. A Word has a Sense in that it points to a given Unit of Meaning.  The Sense, as such, cannot have any definition, as it only reifies the link between Words and UnitOfMeanings. Here I think is where the confusion has happened until now, as sometimes we had this more elaborated concept of Sense as a unit of meaning, while in WordNet we needed a mere reification of a relation.

 

Thus on the one side, I would be tempted to say that “sense” is a relationship, and as well, for being short, the property: ontolex:sense pretty well holds it, though not for linking to a reified LexicalSense, but for linking to a Unit of Meaning/LexicalConcept. On the other side, fact is that we may need (see above examples) a reification of that sense relationship. We have to keep the two things distinct. Here I would introduce ontolex:Sense exactly as this, not as a UnitOfMeaning, but as a reification of the relation between a Word and Unit of Meaning.

 

So far so good, it seems  I could have widen the path from plain literals to ontoelements instead of shortening it, but actually, if properly planned, we could have very useful properties, which can be exploded into reified objects if and where appropriate. And, most of all, we would keep Linguistic Resources as something usable to enrich ontologies, and not as further ontologies to be mapped.

 

MODEL PROPOSAL:

 

I would propose then the following model:

 

NOTES: 

I left out all the characterization of LexicalEntries, which is obviously important, but separate from this discussion. 

For ease of reading, I’m using  the empty prefix instead of :ontolex here.

 

CLASSES:

:LexicalConcept (or Unit of Meaning, but I’ll use LexicalConcept from now on)

:Sense

:LexicalEntry

 

PROPERTIES:

:sense                  domain: LexicalEntry                     range: LexicalConcept  (note the difference here)

:reference          domain: LexicalConcept               range: non-specified, expect however to “land” on ontoelements.

 

:lexEntry             range: LexicalEntry         merely a construct for the role of LexicalEntries in reifiedRelations, such as :Sense

:lexConcept       range: LexicalConcept   merely a construct for the role of LexicalConcepts in reifiedRelations, such as :Sense

 

 

A :Sense (capital letter) is the reification of the :sense property. Being binary in involving LexicalEntries with their intended meaning (LexicalConcept), ontolex:sense plays well in most of the cases, but, if we need a reification, we may have the following rule:

 

:Sense(y)                            :lexEntry                             :LexicalEntry(x)

:Sense(y)                            :lexConcept                       :LexicalConcept(z)

------------------- --->

:LexicalEntry(x)                :sense                                  :LexicalConcept(z)

 

 

Now, our 3-entity-pattern is, as I said initially:

 

Instof(ontolex:LexicalEntry) –prop(ontolex:sense)–> Instof (ontolex:LexicalConcept) –prop(ontolex:reference)–> An Ontoelement

 

Where InstOf(x) means: “an instance of x”

 

Now, WordNet. Given that:

 

Wordnet:Synset              rdfs:subClassOf               :LexicalConcept

 

We may express things such as:

 

wordnet:syn_n_08225481          ontolex:reference          <http://dbpedia.org/ontology/team> ;

 

thus bringing all of the LexicalEntries already defined in WordNet as synonyms in wordnet:syn_n_08225481, as valid LexicalEntries describing the ontology element dbpedia:team.

 

By no means it holds instead that:

Wordnet:Sense               rdfs:subClassOf               :LexicalConcept

As the former includes constructs made-of elements from the latter.

 

Ah, WordNet would have thus this reified senses, but still a direct connection of the form:

instOf(:LexicalEntry)                      :sense                  instOF(wordnet:Synset)

is possible and is hence welcome

 

As you may see:

 

1)      I preserved the possibility to reify Senses (necessary in WordNet), but separated this Sense reification from the LexicalConcept (or Unit of Meaning) present in the current model. 

2)      I allowed for these LexicalConcepts to be used as elements-in-the-middle of our 3-entities-pattern

 

The sense reification is very important in WordNet (as it may be in other resources), to keep track of very specific things such as word ordering, tag counting, or lexical relations, but while all of these have a very important role in the lexical resource, they are not to the extent of a ontolex binding. The :sense binary relation is more than enough in that context.

Once more, there cannot be any further “semantic” characterization of :Sense. An instance of :Sense cannot have a description, as the description pertains to the LexicalConcept. :Sense, in short, is just an escamotage in RDF to further characterize word-synset pairs with additional data.

 

Really sorry for the…yes..erm… quite long email :-D

 

Cheers,

 

Armando

 

P.S: As said, names might be improved (someone could insist that the pointer to a WordNet synset IS de facto a reference), but I would stress not to let terminology affect our modeling, and instead try later to find the best way to name things if we agree on them (rem tenet…verba sequentur). My only concern is that I was definitely feeling something was not working with the previous modeling, and think this “structure” much better renders our needs and properly exploit linguistic resources in the context of enriching conceptual knowledge.

 

[1] Introduction to WordNet: An On-line Lexical Database George A. Miller, Richard Beckwith, Christiane Fellbaum, Derek Gross, and Katherine Miller


http://wordnetcode.princeton.edu/5papers.pdf