Antecedent selection techniques for high-recall roreference resolution

We investigate methods to improve the recall in coreference resolution by also trying to resolve those definite descriptions where no earlier mention of the referent shares the same lexical head (coreferent bridging). The problem, which is notably harder than identifying coreference relations among mentions which have the same lexical head, has been tackled with several rather different approaches, and we attempt to provide a meaningful classification along with a quantitative comparison. Based on the different merits of the methods, we discuss possibilities to improve them and show how they can be effectively combined

Between anaphora and deixis...the resolution of the demonstrative noun-phrase ‘that N’

Three experiments examined the hypothesis that the demonstrative noun phrase (NP) that N, as an anadeictic expression, preferentially refers to the less salient referent in a discourse representation when used anaphorically, whereas the anaphoric pronoun he or she preferentially refers to the highly-focused referent. The findings, from a sentence completion task and two reading time experiments that used gender to create ambiguous and unambiguous coreference, reveal that the demonstrative NP specifically orients processing toward a less salient referent when there is no gender cue discriminating between different possible referents. These findings show the importance of taking into account the discourse function of the anaphor itself and its influence on the process of searching for the referent

Non-situational functions of demonstrative noun phrases in Lingala (Bantu)

This paper examines the non-situational (i.e., non-exophoric) pragmatic functions of the three adnominal demonstratives, oyo, wand, and yango in the Bantu language Lingala. An examination of natural language corpora reveals that, although native-speaker intuitions sanction the use of oyo as an anaphor in demonstrative NPs, this demonstrative is hardly ever used in that role. It also reveals that wand, which has both situational and discourse-referential capacities, is used more frequently than the exclusively anaphoric demonstrative yango. It is explained that wand appears in a wide range of non-coreferential expression types, in coreferential expression types involving low-salience referents, and in coreferential expression types that both involve highly salient referents and include the speaker's desire to signal a shift in the mental representation of the referent towards a pejorative reading. The use of yango, on the other hand, is only licensed in cases of coreferentiality involving highly salient referents and implying continuation of the same mental representation of the referent. A specific section is devoted to charting the possible grammaticalization paths followed by the demonstratives. Conclusions are drawn for pragmatic theory formation in terms of the relation between form (yango vs. wand) and function (coreferentiality vs. non-coreferentiality)

From Language to Programs: Bridging Reinforcement Learning and Maximum Marginal Likelihood

Our goal is to learn a semantic parser that maps natural language utterances into executable programs when only indirect supervision is available: examples are labeled with the correct execution result, but not the program itself. Consequently, we must search the space of programs for those that output the correct result, while not being misled by spurious programs: incorrect programs that coincidentally output the correct result. We connect two common learning paradigms, reinforcement learning (RL) and maximum marginal likelihood (MML), and then present a new learning algorithm that combines the strengths of both. The new algorithm guards against spurious programs by combining the systematic search traditionally employed in MML with the randomized exploration of RL, and by updating parameters such that probability is spread more evenly across consistent programs. We apply our learning algorithm to a new neural semantic parser and show significant gains over existing state-of-the-art results on a recent context-dependent semantic parsing task.Comment: Proceedings of the 55th Annual Meeting of the Association for Computational Linguistics (2017

Resolving pronominal anaphora using commonsense knowledge

Coreference resolution is the task of resolving all expressions in a text that refer to the same entity. Such expressions are often used in writing and speech as shortcuts to avoid repetition. The most frequent form of coreference is the anaphor. To resolve anaphora not only grammatical and syntactical strategies are required, but also semantic approaches should be taken into consideration. This dissertation presents a framework for automatically resolving pronominal anaphora by integrating recent findings from the field of linguistics with new semantic features. Commonsense knowledge is the routine knowledge people have of the everyday world. Because such knowledge is widely used it is frequently omitted from social communications such as texts. It is understandable that without this knowledge computers will have difficulty making sense of textual information. In this dissertation a new set of computational and linguistic features are used in a supervised learning approach to resolve the pronominal anaphora in document. Commonsense knowledge sources such as ConceptNet and WordNet are used and similarity measures are extracted to uncover the elaborative information embedded in the words that can help in the process of anaphora resolution. The anaphoric system is tested on 350 Wall Street Journal articles from the BBN corpus. When compared with other systems available such as BART (Versley et al. 2008) and Charniak and Elsner 2009, our system performed better and also resolved a much wider range of anaphora. We were able to achieve a 92% F-measure on the BBN corpus and an average of 85% F-measure when tested on other genres of documents such as children stories and short stories selected from the web

Antecedent-based approach to binding in Icelandic and Faroese

This paper examines the standard approach to long-distance reflexives within the Lexical-Functional Grammar framework. This approach defines the binding relation between a reflexive and its non-local antecedent by prescribing the type of syntactic elements which must and must not occur along the path from the reflexive to its antecedent. However, evidence from the Insular Scandinavian languages suggests that the binding relation should be expressed as positive and negative constraints on the path from the antecedent to the reflexive. In other words, I suggest that long-distance reflexives in Icelandic and Faroese are governed by outside-in functional uncertainty, not inside-out functional uncertainty, as is standardly assumed