🤖 AI Summary
Conventional correlational analyses fail to establish causal links between training data and language model (LM) behavior.
Method: We propose a “rewriting history” intervention framework that systematically identifies, modifies, and re-trains on training documents containing target knowledge—leveraging co-occurrence statistics and information retrieval for precise document matching—and quantifies behavioral changes via standardized benchmarks.
Contribution/Results: This work introduces the first controlled, causal data intervention at the training stage, moving beyond observational studies to enable rigorous causal testing of data effects on LM behavior. Experiments demonstrate that localized data rewriting significantly alters model knowledge expression; however, current matching strategies remain insufficient to fully account for knowledge acquisition, revealing the inherent complexity of the mapping between training data and emergent model knowledge.
📝 Abstract
We present an experimental recipe for studying the relationship between training data and language model (LM) behavior. We outline steps for intervening on data batches -- i.e., ``rewriting history'' -- and then retraining model checkpoints over that data to test hypotheses relating data to behavior. Our recipe breaks down such an intervention into stages that include selecting evaluation items from a benchmark that measures model behavior, matching relevant documents to those items, and modifying those documents before retraining and measuring the effects. We demonstrate the utility of our recipe through case studies on factual knowledge acquisition in LMs, using both cooccurrence statistics and information retrieval methods to identify documents that might contribute to knowledge learning. Our results supplement past observational analyses that link cooccurrence to model behavior, while demonstrating that extant methods for identifying relevant training documents do not fully explain an LM's ability to correctly answer knowledge questions. Overall, we outline a recipe that researchers can follow to test further hypotheses about how training data affects model behavior. Our code is made publicly available to promote future work.