https://jongha-jeon-dev.github.io/standarderror/tags/feature-importance/Recent content in Feature-Importance on The Standard ErrorHugo -- 0.123.7en-gbMon, 12 Oct 2026 00:00:00 +0000https://jongha-jeon-dev.github.io/standarderror/lectures/ml-12-impurity/Mon, 12 Oct 2026 00:00:00 +0000https://jongha-jeon-dev.github.io/standarderror/lectures/ml-12-impurity/A forest's default feature importance is computed on the data it was fitted to. On a design where the answer is known, it never ranks the only useful feature first, and ranks it last in 19 of 20 datasets.https://jongha-jeon-dev.github.io/standarderror/lectures/ml-16-permutation/Mon, 12 Oct 2026 00:00:00 +0000https://jongha-jeon-dev.github.io/standarderror/lectures/ml-16-permutation/Shuffle a column and see how much worse the model does: it is the importance episode 12 recommended. It answers a narrower question than it seems to, on rows the shuffle invented.