The Medium Is Not the Message: Deconfounding Document Embeddings via Linear Concept Erasure

Yu Fan, Yang Tian, Shauli Ravfogel, Mrinmaya Sachan, Elliott Ash, Alexander Miserlis Hoyle


Abstract
Embedding-based similarity metrics between text sequences can be influenced not just by the content dimensions we most care about, but can also be biased by spurious attributes like the text’s source or language. These document confounders cause problems for many applications, but especially those that need to pool texts from different corpora. This paper shows that a debiasing algorithm that removes information about observed confounders from the encoder representations substantially reduces these biases at a minimal computational cost. Document similarity and clustering metrics improve across every embedding variant and task we evaluate—often dramatically. Interestingly, performance on out-of-distribution benchmarks is not impacted, indicating that the embeddings are not otherwise degraded.
Anthology ID:
2025.emnlp-main.1634
Volume:
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
32112–32131
Language:
URL:
https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.1634/
DOI:
Bibkey:
Cite (ACL):
Yu Fan, Yang Tian, Shauli Ravfogel, Mrinmaya Sachan, Elliott Ash, and Alexander Miserlis Hoyle. 2025. The Medium Is Not the Message: Deconfounding Document Embeddings via Linear Concept Erasure. In Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing, pages 32112–32131, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
The Medium Is Not the Message: Deconfounding Document Embeddings via Linear Concept Erasure (Fan et al., EMNLP 2025)
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https://preview.aclanthology.org/ingest-emnlp/2025.emnlp-main.1634.pdf
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