KD Capacity Gap · Interactive Explorer · v2

Student Capacity Moderates Knowledge Distillation Effectiveness Yaşar (2026) · arXiv:2605.31191 (v2) · CIFAR-10 · 4 ResNet teacher-student pairs · 5 seeds · validation-based protocol


Four Main Findings (v2)

① Student capacity moderates KD — the only statistically significant gains (p<0.05, Welch) belong to R34 students under Feature-KD (+0.19 / +0.21 pp). Doubling teacher size at fixed teacher accuracy (R50 → R101) leaves the gain unchanged: the moderating variable sits on the student side.

② Feature-KD ≥ Logit-KD in all four pairs — and Feature-KD students land closer to the teacher's T=1 output distribution (KL 0.14–0.19 vs 0.21–0.28) despite never observing teacher logits.

③ Fidelity decouples from accuracy — teacher-student top-1 agreement is flat (95.3–95.5%) across all cells, echoing Stanton et al. (2021): distillation gains ≠ closer imitation.

④ Architecture dominates KD — the CIFAR stem correction is worth +5.5 to +7.2 pp, more than 25× the largest KD gain.

Correction from v1: the gradient-clipping bug blamed in v1 for Feature-KD's underperformance had no measurable effect on controlled re-run (p=0.69; unclipped projection norms ≤0.21 vs threshold 1.0). v1's larger gains are explained by test-set hyperparameter selection.