Lesson 3.1
Hybrid keyword and vector search
Vector search misses exact identifiers; keyword search misses paraphrase. Running both and fusing the rankings covers each one’s blind spot.
Taught byPriya RamanLLMs · RAG · Prompt engineering · Evaluation
Overview
Vector search misses exact identifiers; keyword search misses paraphrase. Running both and fusing the rankings covers each one’s blind spot.
What this lesson covers
- Combine lexical and semantic result sets
- Fuse rankings rather than concatenating them
- Fall back to keyword search when embeddings are unavailable
This lesson sits in Retrieval Quality, part of Retrieval-Augmented Generation from Scratch. It assumes what came before it and leads directly into the next lesson in the module.
In this lesson you will:
- Combine lexical and semantic result sets
- Fuse rankings rather than concatenating them
- Fall back to keyword search when embeddings are unavailable