Ranked Activation Shift for Post-Hoc Out-of-Distribution Detection

ArXi:2604.08572v1 Announce Type: new State-of-the-art post-hoc out-of-distribution detection methods rely on intermediate layer activation editing. However, they exhibit inconsistent performance across datasets and models. We show that this instability is driven by differences in the activation distributions, and identify a failure mode of scaling-based methods that arises when penultimate layer activations are not rectified.