You're building a retrieval layer for a RAG system and need to choose between semantic search, keyword search, and a hybrid approach. The corpus includes both natural language documents and text with exact identifiers like product names, error codes, and API fields.
How would you compare semantic search, keyword search, and hybrid search for a RAG retriever? When would you prefer each one, and how would you evaluate the choice?
Understanding of BM25 keyword retrieval versus dense vector retrievalAbility to reason about mixed query types in RAGEvaluation of retrievers before generation qualityAwareness of grounding, hallucination, and retrieval safety