# Evidence: rag-quality-score-unify

## Code (pre-change)

- `MilvusHybridKnowledgeStore.searchHybrid`：RRF 后并行 dense 回填 L2；BM25-only → `bm25_only_no_dense` + maxL2。
- `KnowledgeEvidencePostProcessor`：一律 `normalizeL2(score)` + domain/entity/keyword/source_type 加分，按 `finalScore` 降序；PRECISE 需 `hasHintSupport`。

## User decisions (grill)

| ID | 结论 |
|---|---|
| Q1 | 一级 label 仅 dense/hybrid；bm25_only 不作正式 label |
| Q2 | 后处理去掉 contains 加分改序，保 originalRank |
| Q3 | 唯一 toQualityScore；后处理统一 |
| Q4 | dense mode 保留作对照 |
| Q7 | 接受 relevance_level / retry 分布变化 |
| Q8 | hybrid quality = **纯 rank 映射** |

## Post-change anchors

- `RetrievalScoreLabels` / `RetrievalScoreNormalizer`
- `MilvusHybridKnowledgeStore`（无 L2 overwrite / 无 bm25_only 发射）
- `KnowledgeEvidencePostProcessor`（rank sort + explain-only L0 overlap）
- OpenSpec delta：`rag-retrieval-quality-score`
- 架构：`mvp/architecture/RAG知识检索架构.md` §6