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Judging, part 2: the input format did the work

The deterministic judge is right but narrow: it knows about two coloured bowls. Any new task needs a judge that reads video. NVIDIA's Flora-Rewarder-27B, a robot-trained outcome scorer, passed where Gemini had failed the day before. The ablation says why, and it is not the robot training.

G-flora

Input exactly as NVIDIA's terminal prompt expects: 64 frames, top and wrist camera side by side, no telemetry, greedy decoding. 50 episodes, 42 successes and 8 failures, bar frozen before any call: at the largest score threshold flagging ≤ 2/42 successes, ≥ 6/8 failures must be flagged.

  • 8/8 failures, 2/42 successes, AUROC 1.00. Successes score 4–5, failures 1–3, including both wrong-object cases and both nested-bowl successes that fooled Gemini.
  • Deterministic (5/5 identical), 0 unparseable, 6 s per episode on an A100, $0.70 total.

Flora's licence is non-commercial, so it is evidence, not a component.

G-flora-abl: fine-tune or format?

Same clip, same prompt, three general models.

Model Successes flagged Failures flagged AUROC Verdict
Qwen3.5-27B (Flora's base, no robot fine-tune) 2/42 7/8 0.91 pass
Qwen3.5-9B 16/42 – 0.75 fail
Gemini 3.8 Flash, 64 JPEGs 3/42 8/8 0.96 narrow fail

Flora's base model, untouched, passes the same bar. The 9B does not. Gemini, which caught 0/8 with sliding windows the day before, catches 8/8 with the whole episode and a terminal question. The fine-tune added a little; the input format (whole episode, both views, one outcome question at the end) and model size did the work.

What goes into the stack

A commercial rewarder fine-tuned from Qwen3.5 on own labels is the planned tier-3 verifier. It pairs with the deterministic judge, never replaces it, and it gets a report card (false positives and negatives against owner labels) on every new task before any of its verdicts enter a training set. That rule is written into v1.5.