🤖 AI Summary
This study addresses the problem of erroneous evidence selection in multi-hop question answering caused by information updates within long-horizon external memory. To mitigate this, we propose CMC, a method employing a "parse-then-traverse" strategy. Specifically, it first leverages large language models to extract and update relational graphs for parsing the current state, and subsequently traces relevant raw records dynamically. This provides the answering model with accurate evidence in a single pass, ensuring that retrieval relies on dynamic states rather than static matching. Experimental results demonstrate that CMC achieves state-of-the-art performance with 78.25% multi-hop accuracy on the FactConsolidation dataset. Furthermore, we introduce MQuAKE-MemStream, a new benchmark designed to facilitate future research in this domain.
📝 Abstract
External memory lets language-model agents answer questions about histories too long for the answer model's context window. Updates create a harder problem than retrieving a recent fact: changing one relation can redirect a multi-hop question to records about an entity absent from the question. We study this update-dependent evidence selection problem and introduce the Contract Memory Compiler (CMC). Before seeing a question, CMC uses a language model to identify relations in the history and record where each one was stated. It applies later updates to determine the current relations, follows them from entities named in the question, and passes the corresponding original records to the answer model in one call. Thus the current state determines which evidence is read, rather than merely refreshing values in a previously selected context. To the best of our knowledge, CMC achieves state-of-the-art multi-hop accuracy on FactConsolidation, reaching 78.25% overall and 61.0% at 262K. With the extracted relations and answer model held fixed, selecting evidence before resolving updates reduces multi-hop accuracy to 21.50%. We also introduce MQuAKE-MemStream, a derived dataset of ordered memory streams built from MQuAKE-Remastered counterfactual cases.