TF‑IDF vs BM25: Statistical Foundations of Text Retrieval for RAG
The article explains how TF‑IDF and BM25 compute term importance, compares their strengths and weaknesses, and shows how these sparse retrieval methods integrate with dense retrieval techniques such as DPR, SPLADE, and ColBERT in Retrieval‑Augmented Generation systems, concluding with a hybrid retrieval decision matrix.
