Radical behaviorism, or the conceptual analysis of behavior, was pioneered by B. F. Skinner and is his "philosophy of the science of behavior."[1] It refers to the philosophy behind behavior analysis, and is to be distinguished from methodological behaviorism—which has an intense emphasis on observable behaviors—by its inclusion of thoughts, emotions, and other internal mental activity in the analysis and theorizing of human and animal psychology.[2] The research in behavior analysis is called the experimental analysis of behavior and the application of this field is called applied behavior analysis (ABA).