KG-CRAFT: Knowledge Graph-based Contrastive Reasoning with LLMs for Enhancing Automated Fact-checking
Vítor N. Lourenço, Aline Paes, Tillman Weyde, Audrey Depeige, Mohnish Dubey
TL;DR
KG-CRAFT introduces a knowledge graph-based contrastive reasoning framework to enhance automated fact-checking with LLMs. It builds a knowledge graph from a claim and its reports, generates KG-grounded contrastive questions, answers them using the reports, and distills the results into a concise evidence summary for veracity prediction. Across LIAR-RAW and RAWFC, KG-CRAFT achieves new state-of-the-art performance, with KG-CRAFT_L3.3 attaining top F1 scores on both datasets and ablations confirming the value of KG-based contrastive reasoning, especially for smaller models. The approach highlights the benefits of structured reasoning and contrastive explanations for robust, interpretable fact-checking in bounded contexts.
Abstract
Claim verification is a core component of automated fact-checking systems, aimed at determining the truthfulness of a statement by assessing it against reliable evidence sources such as documents or knowledge bases. This work presents KG-CRAFT, a method that improves automatic claim verification by leveraging large language models (LLMs) augmented with contrastive questions grounded in a knowledge graph. KG-CRAFT first constructs a knowledge graph from claims and associated reports, then formulates contextually relevant contrastive questions based on the knowledge graph structure. These questions guide the distillation of evidence-based reports, which are synthesised into a concise summary that is used for veracity assessment by LLMs. Extensive evaluations on two real-world datasets (LIAR-RAW and RAWFC) demonstrate that our method achieves a new state-of-the-art in predictive performance. Comprehensive analyses validate in detail the effectiveness of our knowledge graph-based contrastive reasoning approach in improving LLMs' fact-checking capabilities.
