Evaluating Evidence Attribution in Generated Fact Checking Explanations
Rui Xing, Timothy Baldwin, Jey Han Lau
TL;DR
This work tackles the trustworthiness of generated explanations in automated fact-checking by focusing on evidence attribution. It introduces a citation masking and recovery protocol to evaluate how accurately explanations attribute statements to cited evidence, and validates it with human annotators and automated methods. The study shows that while large language models (LLMs) can align with human judgments, even the best models produce imperfect attributions, and human-curated evidence substantially improves attribution quality. Collectively, the findings highlight the need for careful evidence selection and point to promising directions for making fact-checking explanations more transparent and trustworthy, including leveraging LLM-based annotators that closely track human judgments.
Abstract
Automated fact-checking systems often struggle with trustworthiness, as their generated explanations can include hallucinations. In this work, we explore evidence attribution for fact-checking explanation generation. We introduce a novel evaluation protocol -- citation masking and recovery -- to assess attribution quality in generated explanations. We implement our protocol using both human annotators and automatic annotators, and find that LLM annotation correlates with human annotation, suggesting that attribution assessment can be automated. Finally, our experiments reveal that: (1) the best-performing LLMs still generate explanations with inaccurate attributions; and (2) human-curated evidence is essential for generating better explanations. Code and data are available here: https://github.com/ruixing76/Transparent-FCExp.
