Tatsuya Aoyama


2024

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DISRPT: A Multilingual, Multi-domain, Cross-framework Benchmark for Discourse Processing
Chloé Braud | Amir Zeldes | Laura Rivière | Yang Janet Liu | Philippe Muller | Damien Sileo | Tatsuya Aoyama
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)

This paper presents DISRPT, a multilingual, multi-domain, and cross-framework benchmark dataset for discourse processing, covering the tasks of discourse unit segmentation, connective identification, and relation classification. DISRPT includes 13 languages, with data from 24 corpora covering about 4 millions tokens and around 250,000 discourse relation instances from 4 discourse frameworks: RST, SDRT, PDTB, and Discourse Dependencies. We present an overview of the data, its development across three NLP shared tasks on discourse processing carried out in the past five years, and the latest modifications and added extensions. We also carry out an evaluation of state-of-the-art multilingual systems trained on the data for each task, showing plateau performance on segmentation, but important room for improvement for connective identification and relation classification. The DISRPT benchmark employs a unified format that we make available on GitHub and HuggingFace in order to encourage future work on discourse processing across languages, domains, and frameworks.

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J-SNACS: Adposition and Case Supersenses for Japanese Joshi
Tatsuya Aoyama | Chihiro Taguchi | Nathan Schneider
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)

Many languages use adpositions (prepositions or postpositions) to mark a variety of semantic relations, with different languages exhibiting both commonalities and idiosyncrasies in the relations grouped under the same lexeme. We present the first Japanese extension of the SNACS framework (Schneider et al., 2018), which has served as the basis for annotating adpositions in corpora from several languages. After establishing which of the set of particles (joshi) in Japanese qualify as case markers and adpositions as defined in SNACS, we annotate 10 chapters (≈10k tokens) of the Japanese translation of Le Petit Prince (The Little Prince), achieving high inter-annotator agreement. We find that, while a majority of the particles and their uses are captured by the existing and extended SNACS annotation guidelines from the previous work, some unique cases were observed. We also conduct experiments investigating the cross-lingual similarity of adposition and case marker supersenses, showing that the language-agnostic SNACS framework captures similarities not clearly observed in multilingual embedding space.

2023

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What’s Hard in English RST Parsing? Predictive Models for Error Analysis
Yang Janet Liu | Tatsuya Aoyama | Amir Zeldes
Proceedings of the 24th Annual Meeting of the Special Interest Group on Discourse and Dialogue

Despite recent advances in Natural Language Processing (NLP), hierarchical discourse parsing in the framework of Rhetorical Structure Theory remains challenging, and our understanding of the reasons for this are as yet limited. In this paper, we examine and model some of the factors associated with parsing difficulties in previous work: the existence of implicit discourse relations, challenges in identifying long-distance relations, out-of-vocabulary items, and more. In order to assess the relative importance of these variables, we also release two annotated English test-sets with explicit correct and distracting discourse markers associated with gold standard RST relations. Our results show that as in shallow discourse parsing, the explicit/implicit distinction plays a role, but that long-distance dependencies are the main challenge, while lack of lexical overlap is less of a problem, at least for in-domain parsing. Our final model is able to predict where errors will occur with an accuracy of 76.3% for the bottom-up parser and 76.6% for the top-down parser.

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GENTLE: A Genre-Diverse Multilayer Challenge Set for English NLP and Linguistic Evaluation
Tatsuya Aoyama | Shabnam Behzad | Luke Gessler | Lauren Levine | Jessica Lin | Yang Janet Liu | Siyao Peng | Yilun Zhu | Amir Zeldes
Proceedings of the 17th Linguistic Annotation Workshop (LAW-XVII)

We present GENTLE, a new mixed-genre English challenge corpus totaling 17K tokens and consisting of 8 unusual text types for out-of-domain evaluation: dictionary entries, esports commentaries, legal documents, medical notes, poetry, mathematical proofs, syllabuses, and threat letters. GENTLE is manually annotated for a variety of popular NLP tasks, including syntactic dependency parsing, entity recognition, coreference resolution, and discourse parsing. We evaluate state-of-the-art NLP systems on GENTLE and find severe degradation for at least some genres in their performance on all tasks, which indicates GENTLE’s utility as an evaluation dataset for NLP systems.

2022

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Probe-Less Probing of BERT’s Layer-Wise Linguistic Knowledge with Masked Word Prediction
Tatsuya Aoyama | Nathan Schneider
Proceedings of the 2022 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies: Student Research Workshop

The current study quantitatively (and qualitatively for an illustrative purpose) analyzes BERT’s layer-wise masked word prediction on an English corpus, and finds that (1) the layerwise localization of linguistic knowledge primarily shown in probing studies is replicated in a behavior-based design and (2) that syntactic and semantic information is encoded at different layers for words of different syntactic categories. Hypothesizing that the above results are correlated with the number of likely potential candidates of the masked word prediction, we also investigate how the results differ for tokens within multiword expressions.

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Comparing Native and Learner Englishes Using a Large Pre-trained Language Model
Tatsuya Aoyama
Proceedings of the 11th Workshop on NLP for Computer Assisted Language Learning