=Paper=
{{Paper
|id=Vol-1899/OntoLex_2017_paper_2
|storemode=property
|title=Encoding Lexicographic Data in Ontolex: Lessons Learned and Open Questions
|pdfUrl=https://ceur-ws.org/Vol-1899/OntoLex_2017_paper_2.pdf
|volume=Vol-1899
|authors=Thierry Declerck
|dblpUrl=https://dblp.org/rec/conf/ldk/Declerck17
}}
==Encoding Lexicographic Data in Ontolex: Lessons Learned and Open Questions==
https://ceur-ws.org/Vol-1899/OntoLex_2017_paper_2.pdf
Encoding lexicographic Data in lemon:
Lessons learned
Thierry Declerck1, Carole Tiberius2, Eveline Wandl-Vogt3
1
DFKI GmbH, Multilingual Technologies Lab
Stuhlsatzenhausweg.3, 66123 Saarbrücken, Germany
declerck@dfki.de
2
Dutch Language Institute
Postbus 9515, 2300 RA Leiden, Netherlands
Carole.Tiberius@ivdnt.org
3
Austrian Centre for Digital Humanities,
Austrian Academy of Sciences
Sonnenfelsgasse 191010 Vienna, Austria
eveline.wandl-vogt@oeaw.ac.at
Abstract. We describe experiments done in using the lemon model for encod-
ing lexicographic data we got from different sources with distinct coverages.
Our focus is on delivering statements on lessons learned and on questions that
still should be discussed in the lemon community, as a possible input for forth-
coming versions of the model.
Keywords: lexicography, lemon model
1 Introduction
In recent years, we have been experimenting with the use of the Lexicon Model for
Ontologies (lemon)1 for representing lexicographic data. lemon has been developed
within the W3C Ontology-Lexica community group2, building on the version that was
first proposed in the context of the European R&D project “Monnet”3. Members of
the W3C community group started to investigate, in close cooperation with members
of the ENeL Cost Action4, on how this model could be used and possibly extended for
the purpose of the encoding of rich lexicographic data in the context of the Linguistic
Linked Open Data (LLOD) framework5.
1
See https://www.w3.org/2016/05/ontolex/ [accessed 13.07.2017, like all other URLs men-
tioned in this paper]
2
https://www.w3.org/community/ontolex/
3
http://cordis.europa.eu/project/rcn/93713_en.html. See for the first version of lemon:
http://lemon-model.net/
4
ENeL stands for “European Network of e-Lexicography”. See http://www.elexicography.eu/
for more details on this COST Action.
5
See http://linguistic-lod.org/ for more details.
2
The studies we present in this paper are dealing with the “Wörterbuch der
bairischen Mundarten in Österreich” (WBÖ)6 and with the “Algemeen Nederlands
Woordenboek” (ANW)7. Details on the first study are described in [1] and for the
second study in [6]. In this paper we focus on lessons learned and on questions that
still should be discussed in the W3C Ontology-Lexica community, as a possible input
for future versions of the lemon model.
2 The lemon model
The original aim of lemon was to provide for a rich linguistic description for natural
language expressions used in knowledge resources, like taxonomies or ontologies.
This linguistic grounding includes the formal representation of morphological and
syntactic properties of lexical entries as well as the specification of the meaning of
these lexical entries with respect to available knowledge resources, more specifically
formal ontologies. This relation between lexical entries and their meaning to be found
in external ontologies is specified in a core module, which is realising the so-called
ontology-lexicon interface (ontolex). Figure 1 below is giving a graphical overview of
the ontolex module.
Fig. 1. Ontolex: the core module of lemon: Figure created by John P. McCrae for the W3C
Ontology-Lexica Community Group
6
Dictionary of the Bavarian Dialects in Austria: https://www.oeaw.ac.at/acdh/projects/wboe/.
7
General Dutch Dictionary: http://anw.inl.nl/
3
The full list of lemon modules comprises the following items8:
Ontology-lexicon interface (ontolex), which is the core module of lemon
Syntax and Semantics (synsem)
Decomposition (decomp)
Variation and Translation (vartrans)
Linguistic Metadata (lime)
3 The “Wörterbuch der bairischen Mundarten in Österreich“
Our first experiment dealing with the encoding of lexicographic data in lemon in-
volved the “Wörterbuch der bairischen Mundarten in Österreich“ (WBÖ)9, which is a
large-scale dictionary documenting (spoken) languages used in Austria and neighbor-
ing areas such as South Tyrol. WBÖ describes a very large varietal spectrum of the
language spoken in the regions it covers. In addition to “Austriacisms”, the publica-
tion also contains standard German keywords, which have developed a different range
of meaning in the dialects.
3.1 The Dictionary Data of WBÖ
The basis we are working on is an XML representation of the electronic version of the
WBÖ dictionary. As the WBÖ is primarily aimed at scientists it uses for its de-
scriptors complex and rich representation forms. So for example, the strings for repre-
senting headwords in WBÖ can include information about pronunciation or word
formation properties10, etc. A first issue for the encoding of the WBÖ headwords in
lemon-ontolex concerns thus the status of this highly specialized and compact repre-
sentation form. As the lemon model considers usually the “lemma form” of a lexical
entry as its canonical form11, we would tend to give to the corresponding instance of
the ontolex:Form class, as the range of the associated object property onto-
lex:canonicalForm, the lemma form of the original headword as the value of
datatype property ontolex:writtenRep, without the special characters used with
the original headword. And we would encode for example the pronunciation proper-
ties as a value of the related datatype property “ontolex:phoneticRep”12.
Thus marking explicitly all the information related to a headword by corresponding
properties.
The issue we have is how to encode the original headword. We do not consider it
as being potentially an “other form”, in the sense this feature has been introduced in
lemon-ontolex (and similar also in other vocabularies, like SKOS-XL with the “alter-
8
Taken from https://www.w3.org/2016/05/ontolex/
9
Dictionary of the Bavarian Dialects in Austria: https://www.oeaw.ac.at/acdh/projects/wboe/
10
An example of such a headword is “(Ge)pâcht”, where the parentheses mark a prefix and the
circumflex refers to a pronunciation property.
11
See also http://www.w3.org/ns/lemon/ontolex#canonicalForm
12
See Figure 1 for the roles played by those properties.
4
native label”). We can encode the original headword as a “hidden form”, but there
would be a need to associate a comment to this representation, stating that this was
the original form used in the dictionary. In general, the issue we are dealing with con-
cerns the wish to keep information about the way the data was represented in the orig-
inal source. In case we can decompose all the lexical information included in the rich
and compact original representation of the headword and port it to different elements
of lemon, we might then just add a property referring to the original headword string.
We used only the ontolex module for the lemon encoding of WBÖ, and as de-
scribed in [2], it was quite straightforward to encode all the senses related to a head-
word in WBÖ. One addition that was needed to ontolex is related to etymological
information included in WBÖ. For this purpose we need to consider temporal rela-
tions that are more detailed than the currently used “outdated” or similar values that
are available in the LexInfo vocabulary. And WBÖ being a dictionary about dialectal
variations, information about locations are also needed.
We see in the current specifications of the “vartrans” module13 that it covers
among others both diatopic and diachronic lexical variations, but the specifications
also encourage the use of external lexical vocabularies for marking temporal infor-
mation on the usage of a word, this being also relevant for synchronic lexicography. It
will be important to reach a consensus on which vocabulary to use for indicating tem-
poral and local information, similar to the use of the LexInfo vocabulary14 for mark-
ing many morphological and syntactic properties of lexical entries within ontolex.
3.2 The “Questionnaires’’ used for the WBÖ Creation
A very interesting resource associated with WBÖ is provided by the (“Fragebögen”)
(questionnaires) that were used for interviewing people in different regions of Austria
on which words they use for expressing a specific concept. The questionnaires includ-
ed concepts and related definitions that could also represent various senses associated
with one term. Those questionnaires form an important part of the very rich documen-
tary material that was used for the creation of the WBÖ, and which contains an esti-
mated 4 million individual sheets15. This documentary material was entered and digit-
ized between 1993 and 2011 in the so-called database of the Bavarian dialects in Aus-
tria (DBÖ)16.
As those questionnaires represent a very rich combination of conceptual and relat-
ed lexical information, we also investigated the possibility of encoding this infor-
mation in lemon-ontolex. It turned out that the possibility to link lexical entries (and
also lexical senses) to a lexical concept, which is itself a member of a SKOS
13
See for more details on this module: https://www.w3.org/2016/05/ontolex/#variation-
translation-vartrans
14
See http://www.lexinfo.net/ for more details.
15
This information is taken from the German Wikipedia page:
https://de.wikipedia.org/wiki/W%C3%B6rterbuch_der_bairischen_Mundarten_in_%C3%96
sterreich
16
See https://wboe.oeaw.ac.at/projekt/beschreibung/
5
scheme17, is very suitable to represent the type of information that is encoded in both
the questionnaires and the WBÖ dictionary. The questionnaire has been encoded in
the SKOS vocabulary and the ontolex property “isEvokedBy” is linking the concepts
of the questionnaires to the lemon-ontolex lexical entries, while the ontolex property
“lexicalizedSense” is linking the concepts to corresponding WBÖ lexical senses. It is
unclear, if we can still speak of a mental abstraction or unit of thought of lexical en-
tries (as the introduction of the “LexicalConcept” class in ontolex was aiming at), but
the fact is that we can efficiently relate the conceptual background that was developed
as a basis for the creation of a dialectal dictionary to the Lexical Entries in the lemon
representation of this dictionary.
Based on our piloting work, the questionnaires are now completely conceptually
interlinked and all sources made available for conceptual based discovery within the
project exploreAT! 18
3.3 The Paper Slips used for the WBÖ Creation
An additional artefact that was used for crafting the dictionary is a (huge) set of paper
slips, on which the field lexicographer was indicating the answer of the interviewed
persons, with some metadata (location, time, and any other comments). Those paper
slips are for sure an important element of cultural heritage, but besides this they also
offer – together with the questionnaires – a view on the methodology, the “workflow”
and the material used. We do not foresee to encode this data in lemon-ontolex. We
rather propose to build for this combination of the two artefacts, questionnaires and
paper slips, a model using SKOS, and linking the concepts of those SKOS schemes to
the lexical entries we have in lemon-ontolex. All the dialectal variants that were en-
coded in the paper slips (and those already present in WBÖ) will then be encoded in
the lemon module “vartrans”.
3.4 First Conclusions
Our aim in the WBÖ case was to develop a series of methodological prototypes of a
machine-readable and modular version of the lexicographical work, aiming at making
it available in the Linguistic Linked Open Data framework. We also suggest ways for
encoding in SKOS some information on data material that was used for the creation
of the original dictionary. But for this, the open question remains if we should aim at
creating a new module in lemon, which is collecting all those aspects of a lexico-
graphic work, and not only the lexical knowledge expressed in the dictionary.
Our learnings and prototypes are further explored within the project exploreAT! to
open up the resources for multicultural, multilingual knowledge discovery.
17
See again for details Figure 1.
18
exploreAT! exploring austria´s culture with the language glass.
https://exploreat.grial.eu/dashboard (last accessed: June, 12th 2017).
6
4 The „Algemeen Nederlands Woordenboek“
A second source of data we have been working with is the XML representation of the
online version of the Algemeen Nederlands Woordenboek (ANW). ANW is an
online, corpus-based, scholarly dictionary of contemporary standard Dutch in the
Netherlands and in Flanders, describing the Dutch vocabulary from 1970 onwards
(see [3]). One of the innovative features of the ANW is that it offers a twofold mean-
ing description: definitions are accompanied by a semagram, a frame-based represen-
tation of knowledge typically associated with a word (see [4]).
The ANW is a digitally-born dictionary. It is very rich data encoded in a format
that is already very abstract. With the addition of the semagram framework, the ANW
includes also some accompanying data structure reflecting the conceptual world to
which lexical entries are related. A nice aspect of the ANW is that it also refers to an
external resource for the information on etymology. Thus a high level of modularity
and connectivity is already realized.
Like a number of scholarly dictionaries, ANW has a large number of senses asso-
ciated to the entries (at least for certain categories of entries – nouns, verbs, etc.). As
this repository of senses is large and complex, a discussion arose if we should not
introduce in lemon a sub-sense hierarchy, which is present in ANW, where a number-
ing strategy is used for representing the hierarchy of senses. We note that a former
version of the lemon model19 included the notion of “subsense”. But the property
defined in this version was meant to describe the composition of senses needed for
describing the composition of senses resulting from the argument structure of a verb
(or another category introducing syntactic arguments). In the new version of lemon,
resulting from the W3C community group discussions, this aspect is dealt with by the
synsem module and the notion of “subsense” has disappeared.
For the time-being we suggested to have in lemon-ontolex a flat list of senses and
to interrelate those by the use of corresponding properties, such as lexin-
fo:hypernym, lexinfo:partHolonym, lexinfo:substanceMeronym,
lexinfo:pertainsTo, etc. As a matter of fact, it turned out that the LexInfo
vocabulary is here (and in general) very helpful for describing relational properties of
lexical senses. But we kept the original ANW numbering for naming the senses object
in lemon-ontolex. Extending the study we describe in this paper to other scholarly
dictionaries will certainly help in getting final decisions on this issue.
For the porting of the verbs included in the ANW we also started to investigate the
use of the synsem module. A first comment would be that we are not sure about the
necessity to use the ontology mappings, as described in the specification document20.
It seems to introduce a higher level of complexity. And the need to introduce a frame
element for each verb seems also to introduce a lot of redundancies. But we have no
alternative solutions for the time being. Our tentative modelling of the verb “eten” (to
eat) looks like in the following:
19
http://lemon-model.net/lemon-cookbook.pdf
20
See again https://www.w3.org/community/ontolex/wiki/Final_Model_Specification
7
:lex_eten_47968
rdf:type ontolex:Word ;
lexinfo:partOfSpeech lexinfo:verb ;
ontolex:canonicalForm :form_eten_infinitive ;
ontolex:sense
;
synsem:synBehavior :eten_frame_1 ;
.
rdf:type ontolex:LexicalSense ;
skos:definition "iets als voedsel tot zich nemen; iets opeten;
iets nuttigen"@nl ; #(take something as food, eat something, …)
ontolex:isLexicalizedSenseOf :Semagram_activiteit ;
ontolex:isLexicalizedSenseOf :Semagram_handeling ;
ontolex:isSenseOf :lex_eten_47968 ;
synsem:objOfProp :eten_frame_obj_1 ;
synsem:subjOfProp :eten_frame_subj_1 ;
.
:eten_frame_1
rdf:type lexinfo:TransitiveFrame ;
rdf:type synsem:SyntacticFrame ;
lexinfo:directObject :eten_frame_obj_1 ;
lexinfo:subject :eten_frame_subj_1 ;
rdfs:comment "one syntactic frame for the Dutch verb
\"eten\""@en ;
rdfs:label "transitief eten"@nl ;
.
:eten_frame_subj_1
rdf:type lexinfo:Subject ;
rdf:type synsem:SyntacticArgument ;
rdfs:comment "A subject of the eten_frame" ;
rdfs:label "subject 1 for eten_frame"@en ;
ontolex:concept :SemaGram_dier ;
ontolex:concept :SemaGram_mens ;
.
:eten_frame_obj_1
rdf:type lexinfo:DirectObject ;
rdf:type synsem:SyntacticArgument ;
rdfs:comment "An object of the eten_frame"@en ;
rdfs:label "object 1 for eten_frame"@en ;
ontolex:concept :SemaGram_voedsel ;.
8
:OntoMap_eten_1
rdf:type synsem:OntoMap ;
rdfs:comment "Mapping the syntacic frame eten_1 with seman-
tics" ;
rdfs:label "OntoMap_eten_1@en}" ;
synsem:objOfProp :eten_frame_obj_1 ;
synsem:ontoMapping ;
synsem:subjOfProp :eten_frame_subj_1 ;
.
But as mentioned above, we have the feeling that this representation is getting too
complex.
We also tested the decomposition module for encoding Dutch compounds with the
example word being “wijnfles” (bottle of wine). As above for the “eten” verb, we just
display the current code, so that the reader can get a concrete idea of the possibility
offered by this “decomposition” module of lemon:
:wijnfles
rdf:type ontolex:MultiWordExpression ;
"\"de\"" ;
lexinfo:gender lexinfo: commonGender ;
lexinfo:partOfSpeech lexinfo:commonNoun ;
lexinfo:partOfSpeech lexinfo:noun ;
rdf:_1 :comp_wijn_1 ;
rdf:_2 :comp_fles_1 ;
:comp_fles_1 ;
:comp_wijn_1 ;
;
:lex_fles_18089 ;
ontolex:sense
;
.
:lex_wijn_182155
rdf:type ontolex:Word ;
"\"de\"" ;
lexinfo:gender lexinfo:masculine ;
lexinfo:partOfSpeech lexinfo:commonNoun ;
lexinfo:partOfSpeech lexinfo:noun ;
ontolex:canonicalForm :form_wijn_singular ;
ontolex:otherForm :form_wijnen_plural ;
9
ontolex:sense ;
.
:lex_fles_18089
rdf:type ontolex:Word ;
"\"de\"" ;
lexinfo:gender lexinfo:feminine ;
lexinfo:gender lexinfo:masculine ;
lexinfo:partOfSpeech lexinfo:commonNoun ;
lexinfo:partOfSpeech lexinfo:noun ;
ontolex:canonicalForm :form_fles_singular ;
ontolex:otherForm :form_flessen_plural ;
.
:comp_fles_1
rdf:type ;
;
:lex_fles_18089 ;
.
:comp_wijn_1
rdf:type ;
;
;
.
The only addition we suggest here, is to add the possibility to have a sense as the
value of the “correspondsTo” property, as this can be seen for the element
“comp_wijn_1” above. The point being that in this case the component “wijn” can
only refer to the generic use of the word, which is the one covered by the Lexical
Sense “sense_wijn1.0”, as can be seen below:
rdf:type ontolex:LexicalSense ;
skos:definition "alcoholhoudende drank, verkregen door gisting
van het sap van druiven of van andere vruchten, met een middel-
matig alcoholgehalte van doorgaans ongeveer 12 procent; alco-
holhoudende drank van gegist druivensap" ;
ontolex:isLexicalizedSenseOf :Concept_325624 ;
ontolex:isLexicalizedSenseOf :Concept_Stofnaam ;
ontolex:isSenseOf :lex_wijn_182155 ;
10
ontolex:reference ;
ontolex:usage lexinfo:massNoun ;
ontolex:usage lexinfo:singular ;
.
This way, it seems that we can cover most (if not all) of the relevant conceptual
and lexical elements included in the ANW offer. A remaining question being if one
needs to introduce in lemon a hierarchy of senses, or rather, like we opted for now, if
one can adopt a single listing of Lexical Senses and to explicitly mark the relation
among them by the use of a possibly extended LexInfo vocabulary.
5 Conclusions
It is our conviction that a lot of the original dictionary data, in different formats and
with different coverages, can be accurately modelled with the lemon modules. Rele-
vant lexicographic information that is not directly related to the description of the
entries (in the sense of providing knowledge about the words) can be designed in or
re-used from models external to lemon, but a consensus building on the best vocabu-
laries to be used will be needed in this case.
And our current intuition is that elements in lemon should not include (deeper) hi-
erarchical structures but represent the relation between elements of the lexicon by the
use of specialized properties. We think this is an aspect that should be discussed and
possibly fixed within the W3C Ontology-Lexica community.
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