\chapter{Bias, Variance and Overfitting}  
\label{chap:overfit} 

GIVE EX FROM 132.TEX ON DENSITY ESTIMATION AT A POINT OF RISING DENSITY,
MAYBE AT ENDPOINT OF SUPPORT, SO HAVE A CLEAR BIAS; MATH DERIVATION

APPLY TO K IN KNN, RANK OF MATRIX, FIXED- VS. RANDOM-EFFECTS IN STAT
MODEL, VALUE OR NOT TO USING COVARS