Night-before cheat sheet

Part IV: Information Retrieval & RAG

9 chapters (57–65). 0 key facts to review.

Chapters at a glance

57 Information retrieval primer: TF-IDF, BM25, why they still matter
58 Dense retrieval: embeddings, contrastive learning, MTEB
59 Vector index internals: HNSW, IVF, ScaNN, FAISS
60 Hybrid search and fusion
61 Chunking strategies
62 Reranking with cross-encoders
63 Query rewriting, HyDE, multi-query, query decomposition
64 RAG evaluation: Ragas, LLM-as-judge, golden sets
65 Designing a RAG system end to end

Key facts (from quizzes)

Other parts
Part I Part II Part III Part IV Part V Part VI Part VII Part VIII Part IX Part X