Statistical significance of observed performance differences
Ascertain whether the observed performance differences between VulGNN and the baseline detectors (including ReVeal, RoBERTa, CodeBERT, GraphCodeBERT, GPT-2 Base, CodeGPT, PolyCoder, T5 Base, CodeT5 Small/Base, and NatGen) are statistically significant rather than due to chance by applying appropriate significance tests to precision, recall, F1-score, accuracy, and false positive rate results under the DiverseVul evaluation setups (“Train on Prev+Diverse, Test on Unseen Projects” and “Train and Test on Prev+Diverse with no overlaps”).
References
Finally, since we did not perform statistical tests, we cannot formally assess whether observed differences between models are significant or due to chance.
Our seed count is small: three seeds suffice for the exact test on the headline last-place ranking ($p \approx 0.037$; conservative variants 0.074 and 0.111) but not for tight variance estimates, so the seed-44 inversion between the two F1 shapes is left open rather than resolved.
We present MultiAttenGastro not as a demonstrated best-in-class attention module --- our own multi-seed comparison could not distinguish it with statistical confidence from CBAM or Coordinate Attention on the one dataset where it performs best (Sect.~\ref{sec:attn-comparison}) but as a concrete case study and a diagnostic protocol (multi-seed ablation, CKA, significance testing) for identifying when multi-dimensional attention is likely to help GI endoscopy models, and when it is likely to add redundant capacity instead.