Using Syntax to Resolve NPE in English

Abstract

This paper describes a novel, syntax-based system for automatic detection and resolution of Noun Phrase Ellipsis (NPE) in English. The system takes in free input English text, detects the site of nominal elision, and if present, selects potential antecedent candidates. The rules are built using the syntactic information on ellipsis and its antecedent discussed in previous theoretical linguistics literature on NPE. Additionally, we prepare a curated dataset of 337 sentences from wellknown, reliable sources, containing positive and negative samples of NPE. We split this dataset into two parts, and use one part to refine our rules and the other to test the performance of our final system. We get an F1-score of 76.47% for detection and 70.27% for NPE resolution on the testset. To the best of our knowledge, ours is the first system that detects and resolves NPE in English. The curated dataset used for this task, albeit small, covers a wide variety of NPE cases and will be made public for future work.

Are Ellipses Important for Machine Translation?

“…Demonstrative determiners, quantifiers, etc. can also license nominal ellipses (Khullar, Majmundar, and Shrivastava 2020;Khullar, Anthony, and Shrivastava 2019;Menzel 2017;Halliday and Hasan 1976).…”

“…Previous computational work on ellipsis resolution has mostly focused on Verb Phrase Ellipsis (VPE), gapping and sluicing; for instance, the detection of VPE in the Penn Treebank using pattern match (Hardt 1992), a transformation learning-based approach to generated patterns for VPE resolution (Hardt 1998), the domain independent VPE detection and resolution using machine learning (Nielsen 2003), automatically parsed text (Nielsen 2004), sentence trimming methods (McShane, Nirenburg, and Babkin 2015), linguistic principles (McShane and Babkin 2016), improved parsing techniques that encode elided material dependencies for reconstruction of sentences containing gapping (Schuster, Nivre, and Manning 2018), discriminative and margin infused algorithms (Dean, Cheung, and Precup 2016), Multilayer Perceptrons (MLP) and Transformers (Zhang et al 2019). Computational work on noun ellipsis is comparatively sparse, comprising a simple rule based system (Khullar, Anthony, and Shrivastava 2019), an annotated corpus for noun ellipsis in movie dialogues (Khullar, Majmundar, and Shrivastava 2020), and end-to-end resolution pipeline experiments with statistical and neural model experiments (Khullar 2020).…”

Why Find the Right One?

“…Trained and tested on one-third of the OntoNotes dataset annotated as the SAnaNotes corpus, their system achieves 61.80% F1 score on the detection of all anaphoric relations, including one-anaphora. The detection and resolution of the determinative one anaphor, on the other hand, has been carried out as a part of computational research on noun ellipsis (Khullar et al, 2020b(Khullar et al, , 2019.…”

“…We prepare three test sets-the first containing sentences with determinative anaphoric ones; the second containing one-anaphora; and the third containing regular non-anaphoric one words. For the first test set, we randomly choose 750 sentences from the NoEl corpus (Khullar et al, 2020b), the curated dataset prepared by (Khullar et al, 2019) and the sAnaNotes corpus (Recasens et al, 2016); for the second, we take 750 sentences from (Khullar et al, 2020a) and (Recasens et al, 2016); and for the third, pick 750 sentences each from Cornel movie dialogs dataset (Danescu-Niculescu-Mizil and Lee, 2011) and The British National Corpus (2001), manually checked to contain non-anaphoric ones. We also undertake translation of these 2,250 sentences to assist automatic evaluation.…”

Finding The Right One and Resolving it

“…In ellipsis theory, this determinative one word here is not one-anaphora, but the licensor or trigger of an elided noun. Detection and resolution of this determinative one anaphor has actually been carried out in a part of our previous computational research on ellipsis (Khullar et al, 2020(Khullar et al, , 2019 Right from Baker (1978), the traditional linguistic literature on one-anaphora and noun ellipsis too has confused between the noun and determiner uses of the word one, using them interchangeably in discussions and analysis. The faulty understanding on this phenomenon in earlier syntactic discourse,…”