CSIRO-LT at SemEval-2026 Task 2: In-the-Wild Valence and Arousal Forecasting on Ecological Text Time Series

Jiyu Chen, Necva Bölücü, Sarvnaz Karimi, Diego Molla, Cecile Paris


Abstract
Predicting emotional valence and arousal in text is challenging due to the continuous, dynamic, and context-dependent nature of emotions. The SemEval 2026 Task 2: Predicting Variation in Emotional Valence and Arousal over Time from Ecological Essays shared task investigates longitudinal affect prediction from real-world personal essays, including forecasting short-term state and longer-term dispositional changes. We compare Pre-trained Language Models (PLMs) and Large Language Models (LLMs) for these subtasks, examining different input representations and feature formulations. We show that sentiment-aware PLMs are most effective for continuous valence and arousal prediction, and LLMs are effective for short-term state forecasting. Modelling dispositional changes remains challenging, and none of our neural approaches surpass simple a historical baseline approach in this setting.
Anthology ID:
2026.semeval-1.24
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:
160–166
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.24/
DOI:
Bibkey:
Cite (ACL):
Jiyu Chen, Necva Bölücü, Sarvnaz Karimi, Diego Molla, and Cecile Paris. 2026. CSIRO-LT at SemEval-2026 Task 2: In-the-Wild Valence and Arousal Forecasting on Ecological Text Time Series. In Proceedings of the 20th International Workshop on Semantic Evaluation (2026), pages 160–166, San Diego, California, USA. Association for Computational Linguistics.
Cite (Informal):
CSIRO-LT at SemEval-2026 Task 2: In-the-Wild Valence and Arousal Forecasting on Ecological Text Time Series (Chen et al., SemEval 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.semeval-1.24.pdf