Simultaneous Feature Selection and Hyperparameter Tuning of K-Nearest Neighbors for Glass Classification: A Comparative Study of Artificial Bee Colony, Simulated Annealing, and Hill Climbing

Glass identification is essential in forensic science and industrial uses. However, the effectiveness of classification algorithms heavily relies on selecting the correct hyperparameters and relevant features. This study investigates the efficacy of three optimization algorithms—Artificial Bee Colony (ABC), Simulated Annealing (SA), and Hill Climbing (HC)—for optimizing the k value, which is the neighbor value of the k-Nearest Neighbors (k-NN) classifier, the distance measure expressing the proximity between two samples, and the feature subset of the UCI Glass Identification dataset. By reframing the classification problem as a multi-dimensional optimization task, the algorithms are assessed based on accuracy, precision, recall, and F1 score. The results show that the population-based ABC algorithm, as a meta-heuristic approach, outperforms local search methods by avoiding local optima and effectively reducing the dimensionality of the data. RI (refractive index) and Mg (magnesium oxide content) emerge as particularly discriminative features. The study demonstrates that combining automatic parameter tuning with feature selection can substantially enhance the predictive performance of k-NN in complex classification tasks.