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Robotics CUPID candidate measurement v1

This convention describes pre-training measurements for candidate demonstration sets in the prospective RoboMimic Can v1.4.1 study. It preserves the study's native CUPID influence rankings, operator tiers, and demonstration lengths. It does not reinterpret them as RLVR advantage mass or as downstream policy performance.

Measurement subject and contract

The subject is the three-checkpoint scoring-policy ensemble frozen by the study. Each checkpoint produces a CUPID performance-influence score for every demonstration using closed-loop rollouts that contain both successes and failures. The native pipeline converts each checkpoint's scores to ordinal ranks, averages those ranks by demonstration, and freezes candidate membership before candidate-policy outcomes are opened.

Profiles are comparable only when they share the same source dataset digest, scoring-policy ensemble, aggregation rule, adapter revision, and complete coordinate definitions.

Coordinates

mean_cupid_rank_percentile

For demonstration $i$, let $r_{si}\in{0,\ldots,n-1}$ be its ordinal CUPID rank at scoring checkpoint $s$, with larger ranks denoting larger influence scores. For candidate $E$,

$$ R(E)=\frac{1}{|E|(n-1)}\sum_{i\in E}\frac{1}{S}\sum_{s=1}^{S}r_{si}. $$

The unit is rank percentile, the sample count is the number of selected demonstrations, and ties follow the frozen numeric demonstration-ID rule. This coordinate measures the candidate's position under the pre-training influence estimator. Its direction is contextual until candidate outcomes test whether higher ranks imply greater downstream utility.

operator_tier_effective_coverage

Let $n_k(E)$ be the number of selected demonstrations from operator tier $k$ for the three frozen tiers. Coverage is

$$ T(E)=\frac{(\sum_k n_k(E))^2}{3\sum_k n_k(E)^2}. $$

The value lies in $(0,1]$ for a nonempty candidate and equals one when the three tier counts are equal. It measures coverage of the released operator strata, not semantic task diversity.

mean_demonstration_action_steps

This is the arithmetic mean of the official episode lengths for the selected demonstrations. Its unit is action steps per demonstration. It is a property of the candidate data, not the equal optimizer-step budget used for candidate training.

measurement_rank_reliability

This is the mean of the three pairwise Spearman correlations among the ordinal rank vectors from the three scoring checkpoints. It is shared by candidates from one freeze because it qualifies the measurement procedure, not an individual subset.

Candidate and probe context

The profile retains measurements that qualify or describe the candidate without turning them into additional optimization coordinates. Candidate attributes record the frozen construction rule, operator-tier counts, whether the explicit tier-balance correction was applied, and the selected fraction of the 300-item pool. These fields preserve data-quality correction and exposure in their native forms.

The scoring-policy failure rate is computed over the three declared 100-episode rollout panels and remains shared context for all five candidates. It records the policy weakness needed by the influence estimator rather than a candidate-specific outcome. Score missingness is the fraction of the expected 900 demonstration-by-checkpoint influence values that are absent. Both fields retain explicit fraction units. They are not candidate-policy training results.

Qualification and edge cases

The closed-loop probe must contain both success and failure episodes at every scoring checkpoint, every candidate membership digest must match the frozen record, and the reliability gate must satisfy its preregistered Spearman and top-half Jaccard thresholds. Failed checks remain failed qualification states; they are never converted into zero-valued rewards or imputed coordinates.

An empty candidate has no valid profile. Nonfinite influence scores, missing demonstrations, inconsistent episode lengths, opened candidate outcomes, and source or protocol digest mismatches invalidate export. Zero or negative finite measurements remain valid when a future native record defines them; the adapter does not clamp measured values.

Scientific boundary

The five profiles are native pre-outcome measurements for one simulated manipulation task. CLI conformance shows that the candidates can be compared without losing their robotics semantics. It does not establish that CUPID rank, tier coverage, or action length predicts candidate-policy utility. That claim requires the separately gated outcome comparison.