I NUNC-ES: strumenti nuovi per la linguistica dei corpora in spagnolo

After a short presentation of NUNC, a freely available multilingual suite of corpora based on newsgroups texts (querable online at http://www.bmanuel.org/projects/ng-HOME.html), this paper intends to investigate the Spanish subset of data collected in NUNC-ES. A brief description of the Spanish hierarchies is given, and some examples of corpus queries are suggested. The third part of the work presents an outline of future developments, especially the release of a new tagset for Spanish

Linguistics parameters for zero anaphora resolution

Dissertação de mest., Natural Language Processing and Human Language Technology, Univ. do Algarve, 2009This dissertation describes and proposes a set of linguistically motivated rules for zero anaphora resolution in the context of a natural language processing chain developed for Portuguese. Some languages, like Portuguese, allow noun phrase (NP) deletion (or zeroing) in several syntactic contexts in order to avoid the redundancy that would result from repetition of previously mentioned words. The co-reference relation between the zeroed element and its antecedent (or previous mention) in the discourse is here called zero anaphora (Mitkov, 2002). In Computational Linguistics, zero anaphora resolution may be viewed as a subtask of anaphora resolution and has an essential role in various Natural Language Processing applications such as information extraction, automatic abstracting, dialog systems, machine translation and question answering. The main goal of this dissertation is to describe the grammatical rules imposing subject NP deletion and referential constraints in the Brazilian Portuguese, in order to allow a correct identification of the antecedent of the deleted subject NP. Some of these rules were then formalized into the Xerox Incremental Parser or XIP (Ait-Mokhtar et al., 2002: 121-144) in order to constitute a module of the Portuguese grammar (Mamede et al. 2010) developed at Spoken Language Laboratory (L2F). Using this rule-based approach we expected to improve the performance of the Portuguese grammar namely by producing better dependency structures with (reconstructed) zeroed NPs for the syntactic-semantic interface. Because of the complexity of the task, the scope of this dissertation had to be limited: (a) subject NP deletion; b) within sentence boundaries and (c) with an explicit antecedent; besides, (d) rules were formalized based solely on the results of the shallow parser (or chunks), that is, with minimal syntactic (and no semantic) knowledge. A corpus of different text genres was manually annotated for zero anaphors and other zero-shaped, usually indefinite, subjects. The rule-based approached is evaluated and results are presented and discussed

Development of a Spanish Version of the Xerox Tagger

This paper describes work performed withing the CRATER (Corpus Resources And Terminology ExtRaction, MLAP-93/20) project, funded by the Commission of the European Communities. In particular, it addresses the issue of adapting the Xerox Tagger to Spanish in order to tag the Spanish version of the ITU (International Telecommunications Union) corpus. The model implemented by this tagger is briefly presented along with some modifications performed on it in order to use some parameters not probabilistically estimated. Initial decisions, like the tagset, the lexicon and the training corpus are also discussed. Finally, results are presented and the benefits of the mixed model justified. 1 Introduction This paper describes the adaptation work carried out to retarget the Xerox Tagger to Spanish 1 . The Xerox Tagger [Cutting et al., 1992] has as one of its virtues the characteristic of being based on a simple probabilistic model, as it will become clear below. It is also claimed to be languag..