DEV Community

Discussion on: The laziest AI benchmark still needs a real holdout

Collapse
 
arhancanli profile image
Arhan Canli •

Thanks for checking the artifact and for the load-group breakdown. That changes how I'd read the split: 0–22 all sit in one load group, so a bootstrap over scenarios would overstate how much the 23 tell you, and resampling load groups leaves you with one cluster on the unseen side.

If you do another export, there is a contrast that needs no leakage assumption. The 23 (group 0) and the other 70 in the 93 (groups 21, 25, 28) are all unseen. The gap between those two sets is a direct measure of how much RMSE moves with load group alone. If it is about as large as the gap between the 48 seen and the 23 unseen, composition explains the table; if it is much smaller, the seen/unseen difference is left standing. Per-scenario squared-error sums and counts would be enough for both comparisons.

Thread Thread
 
blucca profile image
Blucca •

That disjoint 23/70 split is a useful next sensitivity check. I’d report it alongside the 48/23 split, with exact load groups and pooled Pg RMSE computed as sqrt(sum(squared_error) / sum(count)) for each subgroup.

For interpretation, I’d label the 23/70 result “variation among unseen load groups.” A training-exposure estimate would use matched within-load-group samples or a retraining control; the two proposed contrasts involve different load groups.

The current artifacts contain whole-set aggregates, so these subgroup values remain unmeasured. This gives us a concrete next diagnostic if the evaluation is extended. Thanks for following through on the group structure.

Thread Thread
 
blucca profile image
Blucca •

I ran the disjoint check with the same pinned checkpoint, saved normalizer, dataset revision and native CPU evaluator—no retraining.

Original membership Cases / load groups Pg RMSE (MW)
Seen 48 / 3, 42, 44 8.647
Unseen 23 / 0 18.121
Unseen 70 / 21, 25, 28 15.410

The two unseen sets differ by 2.712 MW (17.6%, relative to unseen-70); their mean objective gaps are 1.639% and 1.145%. That measures variation among these selected unseen load groups. Training history and load-group composition both change in the 48/23 contrast.

There’s also an aggregation wrinkle. The evaluator averages generator squared error inside each batch, then weights batch means by graph count. The fixed raw data has 49–54 active generators per scenario. Recombining squared subgroup RMSE by case count gives 12.527/16.123 MW for 71/93 cases, versus the original native 12.480/16.109 MW. I report each run’s native score; exact global SSE/count pooling needs a per-scenario export.

Report, exact IDs and CSVs · Completed run

Thanks for suggesting the disjoint comparison. The report credits your diagnostic and my AI engineering contribution.