PRISM: A Framework for Producing Interpretable Political Bias Embeddings with Political-Aware Cross-Encoder

Yiqun Sun, Qiang Huang, Anthony Kum Hoe Tung, Jun Yu


Abstract
Semantic Text Embedding is a fundamental NLP task that encodes textual content into vector representations, where proximity in the embedding space reflects semantic similarity. While existing embedding models excel at capturing general meaning, they often overlook ideological nuances, limiting their effectiveness in tasks that require an understanding of political bias. To address this gap, we introduce PRISM, the first framework designed to Produce inteRpretable polItical biaS eMbeddings. PRISM operates in two key stages: (1) Controversial Topic Bias Indicator Mining, which systematically extracts fine-grained political topics and corresponding bias indicators from weakly labeled news data, and (2) Cross-Encoder Political Bias Embedding, which assigns structured bias scores to news articles based on their alignment with these indicators. This approach ensures that embeddings are explicitly tied to bias-revealing dimensions, enhancing both interpretability and predictive power. Through extensive experiments on large-scale datasets, we demonstrate that PRISM outperforms state-of-the-art text embedding models in political bias classification while offering highly interpretable representations that facilitate diversified retrieval and ideological analysis. The source code is available at https://anonymous.4open.science/r/PRISM-80B4/.
Anthology ID:
2025.acl-long.1344
Volume:
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2025
Address:
Vienna, Austria
Editors:
Wanxiang Che, Joyce Nabende, Ekaterina Shutova, Mohammad Taher Pilehvar
Venue:
ACL
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Publisher:
Association for Computational Linguistics
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Pages:
27719–27733
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URL:
https://preview.aclanthology.org/ingestion-acl-25/2025.acl-long.1344/
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Cite (ACL):
Yiqun Sun, Qiang Huang, Anthony Kum Hoe Tung, and Jun Yu. 2025. PRISM: A Framework for Producing Interpretable Political Bias Embeddings with Political-Aware Cross-Encoder. In Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 27719–27733, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
PRISM: A Framework for Producing Interpretable Political Bias Embeddings with Political-Aware Cross-Encoder (Sun et al., ACL 2025)
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PDF:
https://preview.aclanthology.org/ingestion-acl-25/2025.acl-long.1344.pdf