Computational Approach to Anaphora Resolution in Spanish Dialogues

Journal of Artificial Intelligence Research

This paper presents an algorithm for identifying noun-phrase antecedents of pronouns and adjectival anaphors in Spanish dialogues. We believe that anaphora resolution requires numerous sources of information in order to find the correct antecedent of the anaphor. These sources can be of different kinds, e.g., linguistic information, discourse/dialogue structure information, or topic information. For this reason, our algorithm uses various different kinds of information (hybrid information). The algorithm is based on linguistic constraints and preferences and uses an anaphoric accessibility space within which the algorithm finds the noun phrase. We present some experiments related to this algorithm and this space using a corpus of 204 dialogues. The algorithm is implemented in Prolog. According to this study, 95.9% of antecedents were located in the proposed space, a precision of 81.3% was obtained for pronominal anaphora resolution, and 81.5% for adjectival anaphora.


Automated Acquisition of Anaphora Resolution Strategies

AAAI Conferences

Anaphora resolution is an important but still difficult problem for various large-scale natural language processing (NLP) applications, such as information extraction and machine translation. Thus far, no discourse theories have been tested on an empirical basis, and therefore there is no answer to the "best" anaphora resolution algorithm.


FOCUSING AND REFERENCE RESOLUTION IN PUNDIT

AAAI Conferences

ABSTRACT This paper describes the use of focusing in the PUNDIT text processing system.* Focusing, as discussed by [Sidncr1979] (as well as the closely related concept of centering, as discussed by [Groszl983]), provides a powerful tool for pronoun resolution. However, its range of application is actually much more general, in that it can be used for several problelns in reference resolution. Specifically, in the PUNDIT' system, focusing is used for one-ansphora, elided noun phrases, and certain types of definite and illdcfinite noun phrases, in addition to its use for pronouns. Another important feature in the PUNDIT reference resolution system is that the focusing algorithm is based on syntactic constituents, rather than on thematic roles, as in Sidncr's system.


Translation of Pronominal Anaphora between English and Spanish: Discrepancies and Evaluation

arXiv.org Artificial Intelligence

This paper evaluates the different tasks carried out in the translation of pronominal anaphora in a machine translation (MT) system. The MT interlingua approach named AGIR (Anaphora Generation with an Interlingua Representation) improves upon other proposals presented to date because it is able to translate intersentential anaphors, detect co-reference chains, and translate Spanish zero pronouns into English---issues hardly considered by other systems. The paper presents the resolution and evaluation of these anaphora problems in AGIR with the use of different kinds of knowledge (lexical, morphological, syntactic, and semantic). The translation of English and Spanish anaphoric third-person personal pronouns (including Spanish zero pronouns) into the target language has been evaluated on unrestricted corpora. We have obtained a precision of 80.4% and 84.8% in the translation of Spanish and English pronouns, respectively. Although we have only studied the Spanish and English languages, our approach can be easily extended to other languages such as Portuguese, Italian, or Japanese.


Translation of Pronominal Anaphora between English and Spanish: Discrepancies and Evaluation

AAAI Conferences

This paper evaluates the different tasks carried out in the translation of pronominal anaphora in a machine translation (MT) system. The MT interlingua approach named AGIR (Anaphora Generation with an Interlingua Representation) improves upon other proposals presented to date because it is able to translate intersentential anaphors, detect coreference chains, and translate Spanish zero pronouns into English--issues hardly considered by other systems. The paper presents the resolution and evaluation of these anaphora problems in AGIR with the use of different kinds of knowledge (lexical, morphological, syntactic, and semantic). The translation of English and Spanish anaphoric third-person personal pronouns (including Spanish zero pronouns) into the target language has been evaluated on unrestricted corpora. We have obtained a precision of 80.4% and 84.8% in the translation of Spanish and English pronouns, respectively. Although we have only studied the Spanish and English languages, our approach can be easily extended to other languages such as Portuguese, Italian, or Japanese.