実践的RAGシステム：知識ベースから検索拡張生成へ

This lesson introduces Retrieval-Augmented Generation (RAG) as a solution to the limitations of static, "closed-book" LLMs by grounding model responses in dynamic, external knowledge bases. Students will learn to identify the core components of the RAG lifecycle and understand how to design effective document ingestion and retrieval pipelines to ensure factual reliability and traceability.

This lesson explores the strategic importance of data transformation in RAG systems, focusing on how chunking strategies, embedding models, and indexing algorithms impact retrieval performance. Students will learn to balance the precision-recall paradox by defining optimal retrieval units that maintain semantic coherence while managing latency and token constraints.

This lesson explores advanced retrieval optimization by contrasting the semantic strengths of dense vector search with the precision of lexical BM25 retrieval. Students will learn to implement hybrid search architectures, including Reciprocal Rank Fusion (RRF) and Cross-Encoder reranking, to effectively balance semantic intent with exact keyword matching in production RAG systems.

This lesson explores the "Demo Paradox" in Retrieval-Augmented Generation, emphasizing that system reliability depends on integrated pipelines rather than isolated metrics. Students will learn how to ensure trustworthiness through metadata persistence, traceability, and rigorous observability across all stages of the RAG architecture.

This lesson explores the transition from RAG prototypes to production-ready systems by emphasizing architectural reliability, statistical verification, and the importance of handling real-world data entropy. Students will learn to implement observability through full-trace telemetry and design robust pipelines that prioritize system stability and predictable, evidence-based outputs over anecdotal success.