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arXiv 2602.11079cs.LGcs.AI

基于探针的数据归因:发现并缓解LLM微调后的不良行为

Probe-Based Data Attribution: Discovering and Mitigating Undesirable Behaviors in LLM Post-Training

California Institute of Technology(加利福尼亚理工学院)

Frank Xiao, Santiago Aranguri

AI总结:

本文提出基于探针的数据归因方法,通过分析测试提示和偏好对的激活差异向量,识别导致特定行为的数据点,并通过重新训练验证归因。该方法在OLMo 2的生产DPO训练中发现有害行为,过滤数据点可显著减少此类行为。

摘要:

我们提出基于探针的数据归因,一种追踪微调语言模型行为变化到责任训练数据点的方法。通过计算测试提示和偏好对的激活差异向量,并按余弦相似度排序,我们识别出导致特定行为的数据点,并通过重新训练修改数据来验证这些归因的因果性。行为-数据点相似性矩阵的聚类也使能够无监督地发现新兴行为。将其应用于OLMo 2的生产DPO训练,我们发现了诱饵触发的合规性:一种有害行为,其中模型在附加良性格式指令时会合规于危险请求。过滤排名最高的数据点可将这种行为减少63%,而切换其标签可达到78%。我们的方法优于基于梯度的归因和LLM-判断基线,同时比两者便宜超过10倍。这种在真实环境中的模型生物体——从受污染的偏好数据中涌现而非刻意注入——为安全技术提供了现实的基准。

英文摘要:

We propose probe-based data attribution, a method that traces behavioral changes in post-trained language models to responsible training datapoints. By computing activation-difference vectors for both test prompts and preference pairs and ranking by cosine similarity, we identify datapoints that cause specific behaviors and validate these attributions causally by retraining with modified data. Clustering behavior-datapoint similarity matrices also enables unsupervised discovery of emergent behaviors. Applying this to OLMo 2's production DPO training, we surfaced distractor-triggered compliance: a harmful behavior where the model complies with dangerous requests when benign formatting instructions are appended. Filtering top-ranked datapoints reduces this behavior by 63% while switching their labels achieves 78%. Our method outperforms gradient-based attribution and LLM-judge baselines while being over 10 times cheaper than both. This in-the-wild model organism - emerging from contaminated preference data rather than deliberate injection - provides a realistic benchmark for safety techniques.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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