Four Responses to Parameter Perturbation
Effective rank before and after the 4.0× obliteration test
Cage
SimPO
Before15.7
After6.7
Overall geometry contracts sharply.
Compass
Bilateral
Before21.7
After23.7
Overall geometry remains broadly stable.
Spring
Bilateral ablation
Before8.1
After26.5
A low starting rank rebounds above its initial value.
Coat of paint
Constitutional
Before41.9
After39.3
Overall rank holds while refusal disappears.
Selected response
Cage: SimPO
Effective rank contracts from 15.7 to 6.7. In this test, the representation becomes markedly narrower after perturbation; the geometry and the behavior both degrade.
How to read this figure. Effective rank estimates how many independent directions carry substantial variation. More rank is not automatically better. Read it alongside behavior, starting scale, training regime, and the exact perturbation tested.