Nicolas Hiebel


2022

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CLISTER : A Corpus for Semantic Textual Similarity in French Clinical Narratives
Nicolas Hiebel | Olivier Ferret | Karën Fort | Aurélie Névéol
Proceedings of the Thirteenth Language Resources and Evaluation Conference

Modern Natural Language Processing relies on the availability of annotated corpora for training and evaluating models. Such resources are scarce, especially for specialized domains in languages other than English. In particular, there are very few resources for semantic similarity in the clinical domain in French. This can be useful for many biomedical natural language processing applications, including text generation. We introduce a definition of similarity that is guided by clinical facts and apply it to the development of a new French corpus of 1,000 sentence pairs manually annotated according to similarity scores. This new sentence similarity corpus is made freely available to the community. We further evaluate the corpus through experiments of automatic similarity measurement. We show that a model of sentence embeddings can capture similarity with state-of-the-art performance on the DEFT STS shared task evaluation data set (Spearman=0.8343). We also show that the corpus is complementary to DEFT STS.

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CLISTER : Un corpus pour la similarité sémantique textuelle dans des cas cliniques en français (CLISTER : A Corpus for Semantic Textual Similarity in French Clinical Narratives)
Nicolas Hiebel | Karën Fort | Aurélie Névéol | Olivier Ferret
Actes de la 29e Conférence sur le Traitement Automatique des Langues Naturelles. Volume 1 : conférence principale

Le TAL repose sur la disponibilité de corpus annotés pour l’entraînement et l’évaluation de modèles. Il existe très peu de ressources pour la similarité sémantique dans le domaine clinique en français. Dans cette étude, nous proposons une définition de la similarité guidée par l’analyse clinique et l’appliquons au développement d’un nouveau corpus partagé de 1 000 paires de phrases annotées manuellement en scores de similarité. Nous évaluons ensuite le corpus par des expériences de mesure automatique de similarité. Nous montrons ainsi qu’un modèle de plongements de phrases peut capturer la similarité avec des performances à l’état de l’art sur le corpus DEFT STS (Spearman=0,8343). Nous montrons également que le contenu du corpus CLISTER est complémentaire de celui de DEFT STS.

2020

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Dating Ancient texts: an Approach for Noisy French Documents
Anaëlle Baledent | Nicolas Hiebel | Gaël Lejeune
Proceedings of LT4HALA 2020 - 1st Workshop on Language Technologies for Historical and Ancient Languages

Automatic dating of ancient documents is a very important area of research for digital humanities applications. Many documents available via digital libraries do not have any dating or dating that is uncertain. Document dating is not only useful by itself but it also helps to choose the appropriate NLP tools (lemmatizer, POS tagger ) for subsequent analysis. This paper provides a dataset with thousands of ancient documents in French and present methods and evaluation metrics for this task. We compare character-level methods with token-level methods on two different datasets of two different time periods and two different text genres. Our results show that character-level models are more robust to noise than classical token-level models. The experiments presented in this article focused on documents written in French but we believe that the ability of character-level models to handle noise properly would help to achieve comparable results on other languages and more ancient languages in particular.