NLP-FSDM at SemEval-2026 Task 2: Temporal Smoothing and CCC-MAE Optimization for Balanced Longitudinal Affect Assessment
Summary
The NLP-FSDM system, developed for SemEval-2026 Task 2, Subtask 1, addresses longitudinal affect assessment by predicting Valence and Arousal (V & A) scores from sequences of ecological essays and feeling words. This system utilizes ModernBERT-large as its text encoder within a joint regression framework. Optimization is achieved through a Concordance Correlation Coefficient (CCC) loss, augmented by a lightly weighted Mean Absolute Error (MAE) term. To mitigate variance from fine-tuning large transformers on smaller user-specific datasets, a three-seed ensemble is employed. Additionally, a lightweight post-inference temporal smoothing mechanism is applied per user to enhance within-user consistency. The system achieved an rcomposite score of 0.546 for Valence and 0.453 for Arousal, demonstrating stable cross-dimensional performance without explicit sequential dependency modeling.
Key takeaway
For NLP Engineers developing longitudinal affect assessment systems, consider the NLP-FSDM approach to enhance prediction stability. You should integrate ModernBERT-large with a CCC-MAE joint regression loss and employ a three-seed ensemble to reduce fine-tuning variance. Additionally, applying a lightweight, per-user temporal smoothing mechanism post-inference can significantly improve within-user consistency for your time-series predictions, even without explicit sequential modeling.
Key insights
The NLP-FSDM system combines ModernBERT-large with CCC-MAE optimization, ensembling, and temporal smoothing for robust longitudinal affect assessment.
Principles
- CCC loss combined with MAE optimizes joint regression.
- Ensembling reduces variance in fine-tuning large transformers.
- Post-inference temporal smoothing improves within-user consistency.
Method
The NLP-FSDM method involves encoding text with ModernBERT-large, optimizing a joint regression with CCC-MAE loss, using a three-seed ensemble, and applying per-user temporal smoothing post-inference.
In practice
- Apply CCC-MAE for joint regression tasks.
- Use multi-seed ensembling to stabilize transformer fine-tuning.
- Implement per-user temporal smoothing for time-series predictions.
Topics
- Longitudinal Affect Assessment
- SemEval-2026 Task 2
- Valence Arousal Prediction
- ModernBERT-large
- Temporal Smoothing
Best for: AI Scientist, NLP Engineer, Research Scientist
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Editorial summary, takeaway, and curation by AIssential. Original article published by Paper Index on ACL Anthology.