Smoothing splines, K nearest neighbors, bias-variance tradeoff, classification
James et al. Chapter 7.4: Regression splines
James et al. Chapter 7.5: Smoothing splines
James et al. Chapter 3.5: Comparison of linear regression with K-nearest neighbors
James et al. Chapter 2.2: Assessing model accuracy (to the end of 2.2.2: bias-variance trade-off)
James et al. Chapter 2.2.3: The classification setting (including KNN)