Connecting the Knowledge Dots: Retrieval-augmented Knowledge Connection for Commonsense Reasoning

AbstractWhile large language models (LLMs) have achieved remarkable performance across various natural language processing (NLP) tasks, LLMs exhibit a limited understanding of commonsense reasoning due to the necessity of implicit knowledge that is rarely expressed in text. Recently, retrieval-augmented language models (RALMs) have enhanced their commonsense reasoning ability by incorporating background knowledge from external corpora. However, previous RALMs overlook the implicit nature of commonsense knowledge, potentially resulting in the retrieved documents not directly containing information needed to answer questions. In this paper, we propose Retrieval-augmented knowledge Connection, ReConnect, which transforms indirectly relevant documents into a direct explanation to answer the given question. To this end, we extract relevant knowledge from various retrieved document subsets and aggregate them into a direct explanation. Experimental results show that ReConnect outperforms state-of-the-art (SOTA) baselines, achieving improvements of +2.0% and +4.6% average accuracy on in-domain (ID) and out-of-domain (OOD) benchmarks, respectively.