Onto.PT: Towards the Automatic Construction of a Lexical Ontology ...

34 Chapter 3. Related Work
the ELRA catalog 9 .
In MWN.PT’s documentation 10 , its authors refer that the first version of this
resource spans over 17,200 manually validated synsets, which correspond to 21,000
word senses/word forms and 16,000 lemmas, from both European and Brazilian
variants of Portuguese. The MWN.PT synsets are aligned with the translation
equivalent concepts of Princeton WordNet and, transitively, to the MultiWordNets
of Italian, Spanish, Hebrew, Romanian and Latin.
MWN.PT synsets are linked under the semantic relations of hypernymy/hyponymy
and meronymy (part, member and substance) (Santos et al., 2010). Furthermore,
MWN.PT includes the subontologies under the concepts of Person, Organization,
Event, Location, and Art works. The authors of MWN.PT claim that their
resource covers the top ontology with the Portuguese equivalents to all concepts in
the top four layers of Princeton WordNet, to the 98 Base Concepts suggested by the
Global Wordnet Association, and to the 164 Core Base Concepts, indicated by the
EuroWordNet project 11 . However, MWN.PT only covers nouns, while the 164 Core
Base Concepts contain not only 66 concrete and 63 abstract noun synsets, but also
35 abstract verb synsets.
WordNet.Br
WordNet.Br (Dias da Silva et al., 2002) is a wordnet resource for the Brazilian
variant of Portuguese. This project consisted of two main development phases.
First, a team of three linguists analysed five Brazilian Portuguese dictionaries and
two corpora in order to acquire synonymy and antonymy information. This resulted
in the manual creation of synsets, and antonymy relations between them, as well as
the writing of synset glosses and the selection of sentences where the synset occurred.
In a second phase (Dias-da Silva et al., 2006), the WordNet.Br synsets were
manually aligned with the Princeton WordNet synsets, with the help of bilingual
dictionaries. A strategy similar to that suggested by the EuroWordNet project was
followed in this process. After the alignment, the WordNet.Br synsets that were
aligned to Princeton WordNet could inherit the relations of this resource. This
means that WordNet.Br covers the relations of: hypernymy, meronymy, cause and
entailment.
Portuguese thesauri
TeP (Dias-Da-Silva and de Moraes, 2003; Maziero et al., 2008) was originally the
synset-base of WordNet.Br (Dias da Silva et al., 2002), created during its first development
phase. It is maintained by Núcleo Interinstitucional de Lingüística Computacional
(NILC) of the University of São Paulo, in São Carlos, Brazil. Its current
version, TeP 2.0 12 , is publicly available and contains more than 44,000 lexical items,
organised in 19,888 synsets. TeP also contains 4,276 antonymy relations between
synsets.
9The European Language Resources Association (ELRA) catalog is available from
http://catalog.elra.info/ (August 2012)
10Available online from http://mwnpt.di.fc.ul.pt/features.html (August 2012)
11See more about these lists of concepts in http://www.globalwordnet.org/gwa/ewn_to_bc/
topont.htm (August 2012)
12Available from http://www.nilc.icmc.usp.br/tep2/ (August 2012)