Vera Schmitt


2025

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Cross-Refine: Improving Natural Language Explanation Generation by Learning in Tandem
Qianli Wang | Tatiana Anikina | Nils Feldhus | Simon Ostermann | Sebastian Möller | Vera Schmitt
Proceedings of the 31st International Conference on Computational Linguistics

Natural language explanations (NLEs) are vital for elucidating the reasoning behind large language model (LLM) decisions. Many techniques have been developed to generate NLEs using LLMs. However, like humans, LLMs might not always produce optimal NLEs on first attempt. Inspired by human learning processes, we introduce Cross-Refine, which employs role modeling by deploying two LLMs as generator and critic, respectively. The generator outputs a first NLE and then refines this initial explanation using feedback and suggestions provided by the critic. Cross-Refine does not require any supervised training data or additional training. We validate Cross-Refine across three NLP tasks using three state-of-the-art open-source LLMs through automatic and human evaluation. We select Self-Refine (Madaan et al., 2023) as the baseline, which only utilizes self-feedback to refine the explanations. Our findings from automatic evaluation and a user study indicate that Cross-Refine outperforms Self-Refine. Meanwhile, Cross-Refine can perform effectively with less powerful LLMs, whereas Self-Refine only yields strong results with ChatGPT. Additionally, we conduct an ablation study to assess the importance of feedback and suggestions. Both of them play an important role in refining explanations. We further evaluate Cross-Refine on a bilingual dataset in English and German.

2024

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Augmented Political Leaning Detection: Leveraging Parliamentary Speeches for Classifying News Articles
Charlott Jakob | Pia Wenzel | Salar Mohtaj | Vera Schmitt
Proceedings of the 4th Workshop on Computational Linguistics for the Political and Social Sciences: Long and short papers

In an era where political discourse infiltrates online platforms and news media, identifying opinion is increasingly critical, especially in news articles, where objectivity is expected. Readers frequently encounter authors’ inherent political viewpoints, challenging them to discern facts from opinions. Classifying text on a spectrum from left to right is a key task for uncovering these viewpoints. Previous approaches rely on outdated datasets to classify current articles, neglecting that political opinions on certain subjects change over time. This paper explores a novel methodology for detecting political leaning in news articles by augmenting them with political speeches specific to the topic and publication time. We evaluated the impact of the augmentation using BERT and Mistral models. The results show that the BERT model’s F1 score improved from a baseline of 0.82 to 0.85, while the Mistral model’s F1 score increased from 0.30 to 0.31.

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Implications of Regulations on Large Generative AI Models in the Super-Election Year and the Impact on Disinformation
Vera Schmitt | Jakob Tesch | Eva Lopez | Tim Polzehl | Aljoscha Burchardt | Konstanze Neumann | Salar Mohtaj | Sebastian Möller
Proceedings of the Workshop on Legal and Ethical Issues in Human Language Technologies @ LREC-COLING 2024