Generating Zero-shot Abstractive Explanations for Rumour Verification

Fuente: arXiv
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Main Authors: Bilal, Iman Munire, Nakov, Preslav, Procter, Rob, Liakata, Maria
Format: Preprint
Published: 2024
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author Bilal, Iman Munire
Nakov, Preslav
Procter, Rob
Liakata, Maria
author_facet Bilal, Iman Munire
Nakov, Preslav
Procter, Rob
Liakata, Maria
contents The task of rumour verification in social media concerns assessing the veracity of a claim on the basis of conversation threads that result from it. While previous work has focused on predicting a veracity label, here we reformulate the task to generate model-centric free-text explanations of a rumour's veracity. The approach is model agnostic in that it generalises to any model. Here we propose a novel GNN-based rumour verification model. We follow a zero-shot approach by first applying post-hoc explainability methods to score the most important posts within a thread and then we use these posts to generate informative explanations using opinion-guided summarisation. To evaluate the informativeness of the explanatory summaries, we exploit the few-shot learning capabilities of a large language model (LLM). Our experiments show that LLMs can have similar agreement to humans in evaluating summaries. Importantly, we show explanatory abstractive summaries are more informative and better reflect the predicted rumour veracity than just using the highest ranking posts in the thread.
format Preprint
id arxiv_https___arxiv_org_abs_2401_12713
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Generating Zero-shot Abstractive Explanations for Rumour Verification
Bilal, Iman Munire
Nakov, Preslav
Procter, Rob
Liakata, Maria
Computation and Language
The task of rumour verification in social media concerns assessing the veracity of a claim on the basis of conversation threads that result from it. While previous work has focused on predicting a veracity label, here we reformulate the task to generate model-centric free-text explanations of a rumour's veracity. The approach is model agnostic in that it generalises to any model. Here we propose a novel GNN-based rumour verification model. We follow a zero-shot approach by first applying post-hoc explainability methods to score the most important posts within a thread and then we use these posts to generate informative explanations using opinion-guided summarisation. To evaluate the informativeness of the explanatory summaries, we exploit the few-shot learning capabilities of a large language model (LLM). Our experiments show that LLMs can have similar agreement to humans in evaluating summaries. Importantly, we show explanatory abstractive summaries are more informative and better reflect the predicted rumour veracity than just using the highest ranking posts in the thread.
title Generating Zero-shot Abstractive Explanations for Rumour Verification
topic Computation and Language
url https://arxiv.org/abs/2401.12713