Ilias Chalkidis


2022

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LexGLUE A Benchmark Dataset for Legal Language Understanding in EnglishLexGLUE: A Benchmark Dataset for Legal Language Understanding in English
Ilias Chalkidis | Abhik Jana | Dirk Hartung | Michael Bommarito | Ion Androutsopoulos | Daniel Katz | Nikolaos Aletras
Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

Laws and their interpretations legal arguments and agreements are typically expressed in writing leading to the production of vast corpora of legal text Their analysis which is at the center of legal practice becomes increasingly elaborate as these collections grow in size Natural language understanding NLU technologies can be a valuable tool to support legal practitioners in these endeavors Their usefulness however largely depends on whether current state of the art models can generalize across various tasks in the legal domain To answer this currently open question we introduce the Legal General Language Understanding Evaluation LexGLUE benchmark a collection of datasets for evaluating model performance across a diverse set of legal NLU tasks in a standardized way We also provide an evaluation and analysis of several generic and legal oriented models demonstrating that the latter consistently offer performance improvements across multiple tasks

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Challenges and Strategies in Cross-Cultural NLP
Daniel Hershcovich | Stella Frank | Heather Lent | Miryam de Lhoneux | Mostafa Abdou | Stephanie Brandl | Emanuele Bugliarello | Laura Cabello Piqueras | Ilias Chalkidis | Ruixiang Cui | Constanza Fierro | Katerina Margatina | Phillip Rust | Anders Søgaard
Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

Various efforts in the Natural Language Processing (NLP) community have been made to accommodate linguistic diversity and serve speakers of many different languages. However, it is important to acknowledge that speakers and the content they produce and require, vary not just by language, but also by culture. Although language and culture are tightly linked, there are important differences. Analogous to cross-lingual and multilingual NLP, cross-cultural and multicultural NLP considers these differences in order to better serve users of NLP systems. We propose a principled framework to frame these efforts, and survey existing and potential strategies.

2020

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Layer-wise Guided Training for BERT : Learning Incrementally Refined Document RepresentationsBERT: Learning Incrementally Refined Document Representations
Nikolaos Manginas | Ilias Chalkidis | Prodromos Malakasiotis
Proceedings of the Fourth Workshop on Structured Prediction for NLP

Although BERT is widely used by the NLP community, little is known about its inner workings. Several attempts have been made to shed light on certain aspects of BERT, often with contradicting conclusions. A much raised concern focuses on BERT’s over-parameterization and under-utilization issues. To this end, we propose o novel approach to fine-tune BERT in a structured manner. Specifically, we focus on Large Scale Multilabel Text Classification (LMTC) where documents are assigned with one or more labels from a large predefined set of hierarchically organized labels. Our approach guides specific BERT layers to predict labels from specific hierarchy levels. Experimenting with two LMTC datasets we show that this structured fine-tuning approach not only yields better classification results but also leads to better parameter utilization.

2019

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Large-Scale Multi-Label Text Classification on EU LegislationEU Legislation
Ilias Chalkidis | Emmanouil Fergadiotis | Prodromos Malakasiotis | Ion Androutsopoulos
Proceedings of the 57th Annual Meeting of the Association for Computational Linguistics

We consider Large-Scale Multi-Label Text Classification (LMTC) in the legal domain. We release a new dataset of 57k legislative documents from EUR-LEX, annotated with 4.3k EUROVOC labels, which is suitable for LMTC, few- and zero-shot learning. Experimenting with several neural classifiers, we show that BIGRUs with label-wise attention perform better than other current state of the art methods. Domain-specific WORD2VEC and context-sensitive ELMO embeddings further improve performance. We also find that considering only particular zones of the documents is sufficient. This allows us to bypass BERT’s maximum text length limit and fine-tune BERT, obtaining the best results in all but zero-shot learning cases.