HopWeaver: Synthesizing Authentic Multi-Hop Questions Across Text Corpora

Abstract: Multi-Hop Question Answering (MHQA) is crucial for evaluating the model's capability to integrate information from diverse sources. However, creating extensive and high-quality MHQA datasets is challenging: (i) manual annotation is expensive, and (ii) current synthesis methods often produce simplistic questions or require extensive manual guidance. This paper introduces HopWeaver, the first automatic framework synthesizing authentic multi-hop questions from unstructured text corpora without human intervention. HopWeaver synthesizes two types of multi-hop questions (bridge and comparison) using an innovative approach that identifies complementary documents across corpora. Its coherent pipeline constructs authentic reasoning paths that integrate information across multiple documents, ensuring synthesized questions necessitate authentic multi-hop reasoning. We further present a comprehensive system for evaluating synthesized multi-hop questions. Empirical evaluations demonstrate that the synthesized questions achieve comparable or superior quality to human-annotated datasets at a lower cost. Our approach is valuable for developing MHQA datasets in specialized domains with scarce annotated resources. The code for HopWeaver is publicly available.