NLP-FSDM at SemEval-2026 Task 2: Temporal Smoothing and CCC-MAE Optimization for Balanced Longitudinal Affect Assessment

Abdessamad Benlahbib, Zouhir Essalmani, Achraf Boumhidi, Anass Fahfouh, Hamza Alami


Abstract
This paper describes the NLP-FSDM system for SemEval-2026 Task 2, Subtask 1 on longitudinal affect assessment. The task requires predicting Valence and Arousal (V & A) scores for sequences of ecological essays and feeling words written over time. We adopt ModernBERT-large as a text encoder and formulate the task as a joint regression problem optimized using a Concordance Correlation Coefficient (CCC) loss combined with a lightly weighted Mean Absolute Error (MAE) term. To reduce variance induced by fine-tuning large transformers on relatively small user-specific datasets, we employ a three-seed ensemble. Finally, we introduce a lightweight post-inference temporal smoothing mechanism applied per user to improve within-user consistency. Our system achieves an rcomposite of 0.546 for Valence and 0.453 for Arousal, demonstrating stable cross-dimensional performance without explicitly modeling sequential dependencies.
Anthology ID:
2026.semeval-1.49
Volume:
Proceedings of the 20th International Workshop on Semantic Evaluation (2026)
Month:
July
Year:
2026
Address:
San Diego, California, USA
Editors:
Ekaterina Kochmar, Debanjan Ghosh, Kai North, Mamoru Komachi
Venues:
SemEval | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
333–337
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.49/
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Bibkey:
Cite (ACL):
Abdessamad Benlahbib, Zouhir Essalmani, Achraf Boumhidi, Anass Fahfouh, and Hamza Alami. 2026. NLP-FSDM at SemEval-2026 Task 2: Temporal Smoothing and CCC-MAE Optimization for Balanced Longitudinal Affect Assessment. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 333–337, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
NLP-FSDM at SemEval-2026 Task 2: Temporal Smoothing and CCC-MAE Optimization for Balanced Longitudinal Affect Assessment (Benlahbib et al., SemEval 2026)
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https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.49.pdf