hvm-docs/eval/results/post-prefix.md

Retrieval eval — k=5

22 hand-curated queries, generated 2026-09-30 02:40:07

Live container after nomic prefixes + heading-recursive chunking (hvm-docs image b200c5f76c56, Watchtower 2026-09-30T02:36Z). Compared with baseline.md (2026-05-22, pre-prefix).

Retriever	P@1	MRR	Recall@5	nDCG@5	avg latency
dense	0.955	0.966	0.985	0.972	183ms
bm25	0.864	0.882	0.909	0.886	8ms
hybrid_rrf	0.955	0.961	0.955	0.955	113ms
bm25+rerank	0.773	0.827	0.848	0.816	162ms
hybrid_rrf+rerank	0.727	0.813	0.894	0.821	254ms

Dense flipped from worst (May MRR 0.539) to best. Rerank now hurts. search_docs therefore defaults to dense; rerank is opt-in via RERANK_ENABLED.

Dense P@1 miss: create a user account (MRR 0.250).