Oumaima El Khettari
2026
Who Judges the Judge? Evaluating LLM-as-a-Judge for French Medical open-ended QA
Ikram Belmadani | Oumaima El Khettari | Pacôme Constant dit Beaufils | Richard Dufour | Benoit Favre
Proceedings of the 1st Workshop on Linguistic Analysis for Health (HeaLing 2026)
Ikram Belmadani | Oumaima El Khettari | Pacôme Constant dit Beaufils | Richard Dufour | Benoit Favre
Proceedings of the 1st Workshop on Linguistic Analysis for Health (HeaLing 2026)
Automatic evaluation of open-ended question answering in specialized domains remains challenging mainly because it relies on manual annotations from domain experts. In this work, we assess the ability of several large language models (LLMs), including closed-access (GPT-5.1, Gemini-2.5-Pro), open-source general-purpose (Qwen-80B), and biomedical domain-adapted models (MedGemma-27B, Phi-3.5-mini variants), to act as automatic evaluators of semantic equivalence in French medical open-ended QA. Our analysis reveals that LLM-based judgments are sensitive to the source of answer generation: judgement correlation varies substantially across different generator models. Among the judges, MedGemma-27B and Qwen-80B achieve the highest agreement with expert annotations in terms of F1 score and Pearson correlation. We further explore lightweight adaptation strategies on Phi-3.5-mini using supervised fine-tuning (SFT) and Group Relative Policy Optimization (GRPO). Even with 184 training instances, these adaptations significantly improve Phi-3.5’s results and reduce variability across answer generators, achieving performance comparable to larger domain-adapted models. Our results highlight the importance of generator-aware evaluation, the limitations of general-purpose LLMs in domain-specific settings, and the effectiveness of lightweight adaptation for compact models in low-resource scenarios.
MedInjection-FR: Exploring the Role of Native, Synthetic, and Translated Data in Biomedical Instruction Tuning
Ikram Belmadani | Oumaima El Khettari | Pacome Constant Dit Beaufils | Benoit Favre | Richard Dufour
Proceedings of the Fifteenth Language Resources and Evaluation Conference
Ikram Belmadani | Oumaima El Khettari | Pacome Constant Dit Beaufils | Benoit Favre | Richard Dufour
Proceedings of the Fifteenth Language Resources and Evaluation Conference
Instruction tuning has become essential for adapting large language models (LLMs) to follow domain-specific prompts. Yet, in specialized fields such as medicine, the scarcity of high-quality French instruction data limits effective supervision. To address this gap, we introduce MedInjection-FR, a large-scale French biomedical instruction dataset comprising 571K instruction–response pairs drawn from three complementary sources: native, synthetic, and translated data. We design a controlled experimental framework to systematically assess how data provenance affects instruction tuning, using Qwen-4B-Instruct fine-tuned across seven configurations combining these sources. Results show that native data yield the strongest performance, while mixed setups, particularly native and translated, provide complementary benefits. Synthetic data alone remains less effective but contributes positively when balanced with native supervision. Evaluation on open-ended QA combines automatic metrics, LLM-as-a-judge assessment, and human expert review; although LLM-based judgments correlate best with human ratings, they show sensitivity to verbosity. These findings highlight that data authenticity and diversity jointly shape downstream adaptation and that heterogeneous supervision can mitigate the scarcity of native French medical instructions.
Is Clinical Text Enough? A Multimodal Study on Mortality Prediction in Heart Failure Patients
Oumaima El Khettari | Virgile Barthet | Guillaume Hocquet | Joconde Weller | Emmanuel Morin | Pierre Zweigenbaum
Proceedings of the Fifteenth Language Resources and Evaluation Conference
Oumaima El Khettari | Virgile Barthet | Guillaume Hocquet | Joconde Weller | Emmanuel Morin | Pierre Zweigenbaum
Proceedings of the Fifteenth Language Resources and Evaluation Conference
Accurate short-term mortality prediction in heart failure (HF) remains challenging, particularly when relying on structured electronic health record (EHR) data alone. We evaluate transformer-based models on a French HF cohort, comparing text-only, structured-only, multimodal, and LLM-based approaches. Our results show that enriching clinical text with entity-level representations improves prediction over CLS embeddings alone, and that supervised multimodal fusion of text and structured variables achieves the best overall performance. In contrast, large language models perform inconsistently across modalities and decoding strategies, with text-only prompts outperforming structured or multimodal inputs. These findings highlight that entity-aware multimodal transformers offer the most reliable solution for short-term HF outcome prediction, while current LLM prompting remains limited for clinical decision support.
2025
Summarization for Generative Relation Extraction in the Microbiome Domain
Oumaima El Khettari | Solen Quiniou | Samuel Chaffron
Actes de l'atelier Traitement du langage médical à l’époque des LLMs 2025 (MLP-LLM)
Oumaima El Khettari | Solen Quiniou | Samuel Chaffron
Actes de l'atelier Traitement du langage médical à l’époque des LLMs 2025 (MLP-LLM)
We explore a generative relation extraction (RE) pipeline tailored to the study of interactions in the intestinal microbiome, a complex and low-resource biomedical domain. Our method leverages summarization with large language models (LLMs) to refine context before extracting relations via instruction-tuned generation. Preliminary results on a dedicated corpus show that summarization improves generative RE performance by reducing noise and guiding the model. However, BERT-based RE approaches still outperform generative models. This ongoing work demonstrates the potential of generative methods to support the study of specialized domains in low-resources setting.
2024
DrBenchmark: A Large Language Understanding Evaluation Benchmark for French Biomedical Domain
Yanis Labrak | Adrien Bazoge | Oumaima El Khettari | Mickael Rouvier | Pacome Constant Dit Beaufils | Natalia Grabar | Béatrice Daille | Solen Quiniou | Emmanuel Morin | Pierre-Antoine Gourraud | Richard Dufour
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)
Yanis Labrak | Adrien Bazoge | Oumaima El Khettari | Mickael Rouvier | Pacome Constant Dit Beaufils | Natalia Grabar | Béatrice Daille | Solen Quiniou | Emmanuel Morin | Pierre-Antoine Gourraud | Richard Dufour
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)
The biomedical domain has sparked a significant interest in the field of Natural Language Processing (NLP), which has seen substantial advancements with pre-trained language models (PLMs). However, comparing these models has proven challenging due to variations in evaluation protocols across different models. A fair solution is to aggregate diverse downstream tasks into a benchmark, allowing for the assessment of intrinsic PLMs qualities from various perspectives. Although still limited to few languages, this initiative has been undertaken in the biomedical field, notably English and Chinese. This limitation hampers the evaluation of the latest French biomedical models, as they are either assessed on a minimal number of tasks with non-standardized protocols or evaluated using general downstream tasks. To bridge this research gap and account for the unique sensitivities of French, we present the first-ever publicly available French biomedical language understanding benchmark called DrBenchmark. It encompasses 20 diversified tasks, including named-entity recognition, part-of-speech tagging, question-answering, semantic textual similarity, or classification. We evaluate 8 state-of-the-art pre-trained masked language models (MLMs) on general and biomedical-specific data, as well as English specific MLMs to assess their cross-lingual capabilities. Our experiments reveal that no single model excels across all tasks, while generalist models are sometimes still competitive.
Mention-Agnostic Information Extraction for Ontological Annotation of Biomedical Articles
Oumaima El Khettari | Noriki Nishida | Shanshan Liu | Rumana Ferdous Munne | Yuki Yamagata | Solen Quiniou | Samuel Chaffron | Yuji Matsumoto
Proceedings of the 23rd Workshop on Biomedical Natural Language Processing
Oumaima El Khettari | Noriki Nishida | Shanshan Liu | Rumana Ferdous Munne | Yuki Yamagata | Solen Quiniou | Samuel Chaffron | Yuji Matsumoto
Proceedings of the 23rd Workshop on Biomedical Natural Language Processing
Biomedical information extraction is crucial for advancing research, enhancing healthcare, and discovering treatments by efficiently analyzing extensive data. Given the extensive amount of biomedical data available, automated information extraction methods are necessary due to manual extraction’s labor-intensive, expertise-dependent, and costly nature. In this paper, we propose a novel two-stage system for information extraction where we annotate biomedical articles based on a specific ontology (HOIP). The major challenge is annotating relation between biomedical processes often not explicitly mentioned in text articles. Here, we first predict the candidate processes and then determine the relationships between these processes. The experimental results show promising outcomes in mention-agnostic process identification using Large Language Models (LLMs). In relation classification, BERT-based supervised models still outperform LLMs significantly. The end-to-end evaluation results suggest the difficulty of this task and room for improvement in both process identification and relation classification.
2023
Annotation d’interactions hôte-microbiote dans des articles scientifiques par similarité sémantique avec une ontologie
Oumaima El Khettari | Solen Quiniou | Samuel Chaffron
Actes de CORIA-TALN 2023. Actes de l'atelier "Analyse et Recherche de Textes Scientifiques" (ARTS)@TALN 2023
Oumaima El Khettari | Solen Quiniou | Samuel Chaffron
Actes de CORIA-TALN 2023. Actes de l'atelier "Analyse et Recherche de Textes Scientifiques" (ARTS)@TALN 2023
Nous nous intéressons à l’extraction de relations, dans des articles scientifiques, portant sur le microbiome humain. Afin de construire un corpus annoté, nous avons évalué l’utilisation de l’ontologie OHMI pour détecter les relations présentes dans les phrases des articles scientifiques, en calculant la similarité sémantique entre les relations définies dans l’ontologie et les phrases des articles. Le modèle BERT et trois variantes biomédicales sont utilisés pour obtenir les représentations des relations et des phrases. Ces modèles sont comparés sur un corpus construit à partir d’articles scientifiques complets issus de la plateforme ISTEX, dont une sous-partie a été annotée manuellement.
Building a Corpus for Biomedical Relation Extraction of Species Mentions
Oumaima El Khettari | Solen Quiniou | Samuel Chaffron
Proceedings of the 22nd Workshop on Biomedical Natural Language Processing and BioNLP Shared Tasks
Oumaima El Khettari | Solen Quiniou | Samuel Chaffron
Proceedings of the 22nd Workshop on Biomedical Natural Language Processing and BioNLP Shared Tasks
We present a manually annotated new corpus, Species-Species Interaction (SSI), for extracting meaningful binary relations between species, in biomedical texts, at sentence level, with a focus on the gut microbiota. The corpus leverages PubTator to annotate species in full-text articles after evaluating different NER species taggers. Our first results are promising for extracting relations between species using BERT and its biomedical variants.