The Kofferklausur, Revisited

In September 2024, a colleague asked an audience: “What is RAG?” I answered: Kofferklausur [1].

For non-German speakers: a Kofferklausur is an open-book exam. You bring your textbooks, notes, everything. The exam doesn’t test what you memorized — it tests whether you can find the right information and reason about it under pressure.

That analogy stuck with me. A foundation model is the student. RAG is the suitcase full of books. The model doesn’t need to memorize every fact — it needs to know how to find the right one and reason about it. Special-purpose tools beat the Swiss Army knife.