The Machine Learning Advent Calendar Day 1: k-NN Regressor in Excel

The article introduces the k-Nearest Neighbors (k-NN) regressor as a fundamental distance-based machine learning model, demonstrating its implementation and analysis using Excel. It emphasizes the importance of feature scaling and the challenges posed by heterogeneous variables, which can distort distance calculations, thereby affecting prediction accuracy. Through practical examples involving the California Housing and Diamonds datasets, the discussion highlights both the strengths of k-NNsuch as simplicity and interpretabilityand its limitations, underscoring the critical need to carefully define the distance metric to accurately capture real-world data structures.