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

158 Chapter 9. Final discussion
3. Moving from term-based to synset-based semantic relations, without
using the extraction context (chapter 7).
Also, even though the procedure for extracting semantic relations from dictionaries
cannot be seen as novel, in chapter 4 of this thesis we have presented work on
the comparison of the structure and contents in different dictionaries of
Portuguese. For instance, we have shown that many regularities are kept across
the definitions of each dictionary, which enabled us to use the same grammars for
extracting information from all the three dictionaries.
Starting with a set of extracted semantic relations, and combining the aforementioned
procedures in the appearing order, we proposed ECO, a flexible approach
for creating a wordnet-like lexical ontology automatically from text. ECO
was used for Portuguese but, considering that different methods can be used for the
relation extraction step, it is language independent.
During this work, each of the previous procedures was used in the construction
of several lexical-semantic resources. These resources, listed below, are public domain
and may be used together with applications that we hope will contribute for
advancing the state-of-the-art of the computational processing of Portuguese:
• CARTÃO: the largest term-based lexical-semantic network for Portuguese,
larger that PAPEL, which it includes together with relations extracted from
two other dictionaries (chapter 4).
• CLIP: the first fuzzy thesaurus for Portuguese, completely extracted from
dictionaries (chapter 5).
• TRIP: the largest synset-based thesaurus for Portuguese, larger than TeP,
which it includes together with synonymy information acquired automatically
from dictionaries (chapter 6).
• Onto.PT: a new wordnet-like lexical ontology for Portuguese, extracted
automatically from textual resources that covers more than 100,000 concepts
(represented as synsets) and more than 170,000 semantic relations (chapter
8). Currently, Onto.PT contains information from five lexical resources,
but the ECO approach enables the future integration of knowledge from other
sources, and consequently its future expansion. It is an addition and/or an alternative
to existing broad-coverage lexical-semantic resources for Portuguese.
The aforementioned contributions are described in the following scientific publications,
presented in national and international events, including some highly selective
ones. Together with the description of the publication venue, we present, when
available, its acceptance rate and ERA ranking 1 :
• Automatic extraction of semantic relations from Portuguese definitions in
collaborativelly-created resources – Wikipedia, first, and Wiktionary, second:
– Gonçalo Oliveira, H., Costa, H., and Gomes, P. (2010a). Extracção de conhecimento
léxico-semântico a partir de resumos da Wikipédia. In Actas do II
Simpósio de Informática, INFORUM 2010, pages 537–548, Braga, Portugal.
Universidade do Minho (40% acceptance rate)
1 Conference ranking by the Excellence in Research for Australia, see http://core.edu.au/
index.php/categories/conference\%20rankings/1 (August 2012)