AI RESEARCH

The Role of Vocabularies in Learning Sparse Representations for Ranking

arXiv CS.CL

ArXi:2509.16621v2 Announce Type: replace-cross Learned Sparse Retrieval (LSR) such as SPLADE has growing interest for effective semantic 1st stage matching while enjoying the efficiency of inverted indices. A recent work on learning SPLADE models with expanded vocabularies (ESPLADE) was proposed to represent queries and documents into a sparse space of custom vocabulary which have different levels of vocabularic granularity.