Natural Language Counterfactual Explanations in Financial Text Classification: A Comparison of Generators and Evaluation Metrics

Karol Dobiczek, Patrick Altmeyer, Cynthia C. S. Liem


Abstract
The use of large language model (LLM) classifiers in finance and other high-stakes domains calls for a high level of trustworthiness and explainability. We focus on counterfactual explanations (CE), a form of explainable AI that explains a model’s output by proposing an alternative to the original input that changes the classification. We use three types of CE generators for LLM classifiers and assess the quality of their explanations on a recent dataset consisting of central bank communications. We compare the generators using a selection of quantitative and qualitative metrics. Our findings suggest that non-expert and expert evaluators prefer CE methods that apply minimal changes; however, the methods we analyze might not handle the domain-specific vocabulary well enough to generate plausible explanations. We discuss shortcomings in the choice of evaluation metrics in the literature on text CE generators and propose refined definitions of the fluency and plausibility qualitative metrics.
Anthology ID:
2025.gem-1.75
Volume:
Proceedings of the Fourth Workshop on Generation, Evaluation and Metrics (GEM²)
Month:
July
Year:
2025
Address:
Vienna, Austria and virtual meeting
Editors:
Kaustubh Dhole, Miruna Clinciu
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GEM | WS
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Publisher:
Association for Computational Linguistics
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Pages:
958–972
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URL:
https://preview.aclanthology.org/transition-to-people-yaml/2025.gem-1.75/
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Cite (ACL):
Karol Dobiczek, Patrick Altmeyer, and Cynthia C. S. Liem. 2025. Natural Language Counterfactual Explanations in Financial Text Classification: A Comparison of Generators and Evaluation Metrics. In Proceedings of the Fourth Workshop on Generation, Evaluation and Metrics (GEM²), pages 958–972, Vienna, Austria and virtual meeting. Association for Computational Linguistics.
Cite (Informal):
Natural Language Counterfactual Explanations in Financial Text Classification: A Comparison of Generators and Evaluation Metrics (Dobiczek et al., GEM 2025)
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https://preview.aclanthology.org/transition-to-people-yaml/2025.gem-1.75.pdf