Before revision: Conventional sparse retrieval methods such as TF-IDF and BM25 are simple and efficient, but solely rely on lexical overlap without semantic matching. Recent dense retrieval methods learn latent representations to tackle the lexical mismatch problem, while being more computationally expensive and insufficient for exact matching as they embed the text sequence into a single vector with limited capacity. In this paper, we present Generation-Augmented Retrieval (GAR) , a query expansion method that augments a query with relevant contexts through text generation  .
After revision: We propose Generation-Augmented Retrieval (GAR) , a query expansion method that augments a query with relevant contexts through text generation .