Automatic grammar extraction from annotated corpora (Xia, 1999; Chen and Vijay-Shanker, 2000; Chiang, 2000; Hockenmaier and Steedman, 2002; Miyao et al., 2004) enabled us to build a widecoverage lexicalized grammar at low cost. They succeeded in extracting a large number of lexical entries with less effort while conventional methods only allow limited lexical entries to be acquired in realworld...

This paper is concerned with the standardisation of evaluation metrics for lexical acquisition over precision grammars, which are attuned to actual parser performance. Specifically, we investigate the impact that lexicons at varying levels of lexical item precision and recall have on the performance of pre-existing broad-coverage precision grammars in parsing, i.e., on their coverage and accura...

This paper focuses on the central role played by lexical information in the task of Recognizing Textual Entailment. In particular, the usefulness of lexical knowledge extracted from several widely used static resources, represented in the form of entailment rules, is compared with a method to extract lexical information from Wikipedia as a dynamic knowledge resource. The proposed acquisition me...

One reason why the lexical capabilities of NLP systems have remained weak is because of the labour intensive nature of encoding lexical entries for the lexicon. It has been estimated that the average time needed to construct manually a lexical entry for a Machine Translation system is about 30 minutes [Neff et al. 93]. The automatic acquisition of lexical knowledge is the main field of the rese...

We describe three PCFG-based models for Chinese sentence realisation from LexicalFunctional Grammar (LFG) f-structures. Both the lexicalised model and the history-based model improve on the accuracy of a simple wide-coverage PCFG model by adding lexical and contextual information to weaken inappropriate independence assumptions implicit in the PCFG models. In addition, we provide techniques for...

This paper describes morphdb.hu, a Hungarian lexical database and morphological grammar. Morphdb.hu is the outcome of a severalyear collaborative effort and represents the resource with the widest coverage and broadest range of applicability presently available for Hungarian. The grammar resource is the formalization of well-founded theoretical decisions handling inflection and productive deriv...

This paper shows how large-coverage morphological and syntactic NLP lexicons can be developed by interpreting, converting to a common format and merging existing lexical resources. Applied on Spanish, this allowed us to build a morphological and syntactic lexicon, the Leffe. It relies on the Alexina framework, originally developed together with the French lexicon Lefff. We describe how the inpu...

English. We describe an experiment designed to measure the lexical coverage of some resources over the Italian cooking recipes genre. First, we have built a small cooking recipe dataset; second, we have done a qualitative morpho-syntactic analysis of the dataset and third we have done a quantitative analysis of the lexical coverage of the dataset. Italian. Descriviamo un esperimento per valutar...

In this work, we examine and attempt to extend the coverage of a German HPSG grammar. We use the grammar to parse a corpus of newspaper text and evaluate the proportion of sentences which have a correct attested parse, and analyse the cause of errors in terms of lexical or constructional gaps which prevent parsing. Then, using a maximum entropy model, we evaluate prediction of lexical types in ...

High-quality lexical resources are needed to both train and evaluate Word Sense Disambiguation (WSD) systems. The problem of ambiguity persists even in limited domains, thus the necessity for wide-coverage inventories of senses (dictionaries) and corpora sense-tagged to them. WordNet has been used extensively for WSD, for both its broad coverage and its large network of semantic relations. In t...