Platforms & Practice
24 min
Query Understanding Is the Hidden Half of Search: From Broder's Taxonomy to LLM Query Rewriting
An LLM-written pseudo-document lifts BM25 by 15 nDCG@10 points on TREC DL 2019, and turns a 16 ms search into one that waits over two seconds for the model. Query understanding decides what the engine searches for before ranking …