Ensemble member selection refers to algorithms that optimize the composition of an ensemble. This may involve growing an ensemble from available models or pruning members from a fully defined ensemble. The goal is often to reduce the model or computational complexity of an ensemble with little or no effect on the performance of an ensemble, and in some cases find a combination of ensemble members that results in better performance than blindly using all contributing models directly. In this tutorial, you will discover how to develop ensemble selection algorithms from scratch. Growing and Pruning Ensembles in Python Photo by FaBio C, some rights reserved. Voting and stacking ensembles typically combine the predictions from a heterogeneous group of model types.

Machine learning algorithms have hyperparameters that allow you to tailor the behavior of the algorithm to your specific dataset. Hyperparameters are different from parameters, which are the internal coefficients or weights for a model found by the learning algorithm. Unlike parameters, hyperparameters are specified by the practitioner when configuring the model. Typically, it is challenging to know what values to use for the hyperparameters of a given algorithm on a given dataset, therefore it is common to use random or grid search strategies for different hyperparameter values. The more hyperparameters of an algorithm that you need to tune, the slower the tuning process.