Exploration gathers information about the unknown. This information can come in many forms, from knowledge of new terrain, to rock geology, to lifeforms. The value of these different information forms is determined by a set of information metrics, one for each form of information, that depend on the goal of the exploration task. As explorations become more complex, increasing numbers of information metrics must be considered simultaneously during exploration and often conflict with each other to compete for the finite resources of the explorer.This book introduces a new exploration technique which actively considers how much information can be gained from taking sensor readings as well as the cost of collecting this information. The methodology can consider multiple metrics of information simultaneously, and these information metrics can be changed to perform new exploration tasks. Exploration plans are produced which maximize the utility, information gain minus exploration costs, to the exploring robot.