Hyperparameter Optimization via Sequential Uniform Designs

Hyperparameter tuning or optimization plays a central role in the automated machine learning (AutoML) pipeline. It is a challenging task as the response surfaces of hyperparameters are generally unknown, and the evaluation of each experiment is expensive. In this paper, we reformulate hyperparameter optimization as a kind of computer experiment and propose a novel sequential uniform design (SeqUD) for hyperparameter optimization. It is advantageous as a) it adaptively explores the hyperparameter space with evenly spread design points, which is free of the expensive meta-modeling and acquisition optimization procedures in Bayesian optimization; b) sequential design points are generated in batch, which can be easily parallelized; and c) a real-time augmented uniform design (AugUD) algorithm is developed for the efficient generation of new design points. Experiments are conducted on both global optimization tasks and hyperparameter optimization applications. The results show that SeqUD outperforms related hyperparameter optimization methods, which is demonstrated to be a promising and competitive alternative of existing tools.