Yeda AI Knowledge Base
RAG & Vector DBs
Retrieval that finds the right chunk — and refuses to answer when it doesn’t.
Tip #040
Chunk With Overlap: Stop Losing Meaning at the Boundary
Why naive fixed-size chunking breaks RAG answers, and how a recursive splitter with overlap (chunk_size~1000, chunk_overlap~200) fixes it.
Tip #041Refuse On Empty Context: The One Check That Stops RAG Hallucinations
How to add a similarity-score threshold to your RAG pipeline so weak or empty retrieval returns an honest refusal instead of a confident hallucination.
Tip #042Hybrid Search + Rerank: Fix Embeddings' Blind Spot for Exact Matches
Why pure embedding search misses exact-match queries like order numbers, and how combining BM25 keyword search with reranking fixes it — with real NDCG numbers.