Rethinking Loss Functions for Fact Verification
Yuta Mukobara, Yutaro Shigeto, Masashi Shimbo
TL;DR
Two task-specific objectives tailored to FEVER are developed that outperform the standard cross-entropy loss and are combined with simple class weighting, which effectively overcomes the imbalance in the training data.
Abstract
We explore loss functions for fact verification in the FEVER shared task. While the cross-entropy loss is a standard objective for training verdict predictors, it fails to capture the heterogeneity among the FEVER verdict classes. In this paper, we develop two task-specific objectives tailored to FEVER. Experimental results confirm that the proposed objective functions outperform the standard cross-entropy. Performance is further improved when these objectives are combined with simple class weighting, which effectively overcomes the imbalance in the training data. The souce code is available at https://github.com/yuta-mukobara/RLF-KGAT
