ML 9: The Bias–Variance U Belongs to a Knob, Not to Complexity
Disclosure: this post was written with the assistance of an AI system (Claude), which wrote the analysis code, ran the experiments and drafted the text. The topic, the constraints, the data choices and the final review are the author’s. On a simulated regression where bias, variance and noise can be computed exactly, the three add up to the measured test error to within 0.003. For k-nearest neighbours the variance falls from 0....