4 Nonparametric Regression
4.1 Univariate Kernel Regression
4.2 Other Smoothers
4.2.1 Nearest-Neighbor Estimator
4.2.2 Median Smoothing
4.2.3 Spline Smoothing
4.2.4 Orthogonal Series
4.3 Smoothing Parameter Selection
4.4 Confidence Regions and Tests
4.5 Multivariate Kernel Regression