Verifying Test-State Identity in Paired Evaluation of Vision-Language-Action Models
arXiv:2611.00896v1 Announce Type: new Abstract: Simulation-based VLA evaluation often treats matching task, seed, and episode identifiers as sufficient evidence that two policies faced identical test conditions. Under specific vectorized reset and autoreset conditions, different termination timing can change subsequent initial-state assignment, so the same episode index need not mean the same test state. We present an evaluation-integrity framework for paired comparison - invariants I1-I5, provenance logging, optional scene fingerprints, and an automated checker - and a controlled LeRobot 0.6.1 LIBERO harness study with emulated controllers. Four evidence levels are kept separate: (A) mixed-horizon Sync wave-1 IDs [20, 5, 22, 7] vs [4, 5, 6, 7]; (B) homogeneous separate-job Sync control (16 cells, 0 ID/fingerprint mismatches); (C) Async+Freeze batch-size map differences (12 I3 mismatches; bs=8 incomplete; mechanism unisolated); (D) a synthetic McNemar illustration only. Controllers wer