Free Lesson
Cheat at Search Essentials: BM25 + Lexical
60 min
Jan 20, 2026 12:30 PM
Virtual (Zoom)
In this video
What you'll learn
Basics of Information Retrieval
Learn the baseline that rules them all (BM25) and how it works
The importance of tokenization
How the simple decision of how to break up strings can make or break search
Cheat at semantic search without the vectors
How to achieve semantic search without vector search - and why you might prefer a lexical semantic approach
Why this topic matters
It's often said with chat interfaces and RAG, search has become the hard problem. Search has a long history and means more than vector databases. Let's learn how BM25 and similar techniques compliment your vector database. And why you might not want to always reach for embeddings.
Part of "Cheat at Search - Essentials" intro to search course
You'll learn from
Doug Turnbull
Principal AI Engineer in Search
Previously at
