Data Laundering: Artificially Boosting Benchmark Results through Knowledge Distillation

Jonibek Mansurov, Akhmed Sakip, Alham Fikri Aji


Abstract
In this paper, we show that knowledge distillation can be subverted to manipulate language model benchmark scores, revealing a critical vulnerability in current evaluation practices. We introduce “Data Laundering,” a process that enables the covert transfer of benchmark-specific knowledge through seemingly legitimate intermediate training steps. Through extensive experiments with a 2-layer BERT student model, we show how this approach can achieve substantial improvements in benchmark accuracy (up to 75% on GPQA) without developing genuine reasoning capabilities. Notably, this method can be exploited intentionally or even unintentionally, as researchers may inadvertently adopt this method and inflate scores without realising the implications. While our findings demonstrate the effectiveness of this technique, we present them as a cautionary tale highlighting the urgent need for more robust evaluation methods in AI. This work aims to contribute to the ongoing discussion about evaluation integrity in AI development and the need for benchmarks that more accurately reflect true model capabilities. The code is available at https://github.com/mbzuai-nlp/data_laundering.
Anthology ID:
2025.acl-long.407
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
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
8332–8345
Language:
URL:
https://preview.aclanthology.org/ingestion-acl-25/2025.acl-long.407/
DOI:
Bibkey:
Cite (ACL):
Jonibek Mansurov, Akhmed Sakip, and Alham Fikri Aji. 2025. Data Laundering: Artificially Boosting Benchmark Results through Knowledge Distillation. In Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 8332–8345, Vienna, Austria. Association for Computational Linguistics.
Cite (Informal):
Data Laundering: Artificially Boosting Benchmark Results through Knowledge Distillation (Mansurov et al., ACL 2025)
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PDF:
https://preview.aclanthology.org/ingestion-acl-25/2025.acl-long.407.pdf