VLA-JEPA's surprise as a failure warning: a robot day with nothing to warn about¶
We wanted to know if a policy's own world model is surprised before it fails on the arm. We ran it on sealed layouts, some with the bowls moved, with the bar fixed first. It succeeded on 20 of 20, so there was no failure to warn about.
Evaluation and judges · 14 of 14
Type: method · Result: Not proven: VLA-JEPA completed 20 of 20 sealed layouts (9 off-nominal), so there was no failure for its surprise to warn about. · n: 20 rollouts on the arm, 0 failures
Not proven: Whether VLA-JEPA's surprise warns before a failure; a harder layout set is next.
Compute: External GPU: no (Orin NX, arm). Cost: $0. · Reproduce: 2026-10-29-vla-jepa-surprise-robot-day · First published: 2026-10-29 · Updated: 2026-10-29
VLA-JEPA carries its own world model. If that model is surprised when a grasp goes wrong, the policy could warn about its own failures with no extra network. I set a robot day up to test it, and the policy didn't fail once.
The question¶
Does VLA-JEPA's own world-model surprise warn before a failure on the arm, earlier or more reliably than W1's surprise, a joint-stall rule, elapsed time and the REAP risk head? The bar was frozen on 2026-10-25, before the robot day, together with the scorer and a sealed list of 60 layouts across 30 strata, nominal (teleop positions) and off-nominal (each bowl shifted 3–6 cm). A warning only counts if it comes before the failure onset marked by the owner, and the bar needs at least 6 failures before any monitor is scored.
What happened¶
On 2026-10-27 VLA-JEPA (checkpoint c65c98b, Orin NX at MAXN_SUPER, sync loop) ran the sealed layouts in order, the owner placing the bowls and calling each outcome at rest.
| rollouts | success | |
|---|---|---|
| teleop positions | 11 | 11 |
| bowls shifted 3–6 cm | 9 | 9 |
| all | 20 | 20 |
The owner stopped at rollout 20 instead of 60: with no failure in 13 (and one in 10 on the earlier gate), reaching 6 failures in the remaining 47 was about 1–2 % likely, and the bar's branch for fewer than 6 failures doesn't depend on the rollouts not run.
Verdict¶
Not proven: too few failures (0 < 6). No monitor was scored, so this says nothing yet about VLA-JEPA's surprise.
What the day does show: this VLA-JEPA completes the bowls task on 20 of 20 sealed layouts, including 9 with both bowls off their teleop positions. The task is too easy to produce the failures a monitor needs. The next step is a harder layout set, with its own bar written before the run, and we'll come back to it then.
Compute. External GPU: no (Orin NX, arm). Cost: $0.
Reproduce this: 2026-10-29-vla-jepa-surprise-robot-day
Evaluation and judges, 14 of 14. ← Evaluation and judges 13: How I re-test robot-learning papers: the gate protocol as it ran