Strategies
- Vector similarity (semantic)
- Keyword/BM25
- Hybrid (best of both)
Hybrid weighting (alpha)
alpha = 1.0: pure semantic (embeddings)alpha = 0.0: pure keyword- Between 0 and 1 blends the two (default is semantic-heavy)
Hybrid weighting (alpha)
alpha = 1.0: pure semantic (embeddings)alpha = 0.0: pure keyword- Between 0 and 1 blends the two (default is semantic-heavy, e.g., ~0.8)
Reranking
Apply a reranker to reorder top-k for precision.Tuning
- Adjust k and score thresholds
- Use metadata filters
- Group queries by intent (e.g., returns, billing, onboarding) and tune per index
- Choose model per index:
moss-minilm(fast) ormoss-mediumlm(more accurate)