Permutation importance tells you about the model, not the physics: pitfalls explained

bravo_abad · x · 2026-10-27

A practical thread on permutation importance for scientific ML: shuffle one feature column, re-score, and error increase = importance. Two key pitfalls: redundant features (composition-weighted descriptors overlap heavily) can all look unimportant, while shuffling one of two correlated descriptors creates unrealistic inputs that inflate scores—group permutations help. Core principle: feature importance is a property of the model's response to a perturbation, not a claim about physical causality. Essential distinction when using ML for scientific insight.

Original post →

More from Research

Research channel →