The theory of behaviorism concentrates on the study of overt behaviors that can be observed and measured (Good & Brophy, 1990). In general, the behavior theorists view the mind as a “black box” in the sense that response to stimulus can be observed quantitatively, ignoring the possibility of thought processes occurring in the mind. Behaviorists believe that learning takes place as the result of a response that follows on a specific stimulus. By repeating the S-R (stimulus-response) cycle, the organism (may it be an animal or human) is conditioned into repeating the response whenever the same stimulus is present. The behavioral emphasis on breaking down complex tasks, such as learning to read, into subskills that are taught separately has a powerful influence on instructional design. Behaviors can be modified, and learning is measured by observable change in behavior. The behavior theorists emphasize the need of objectivity, which leads to great accentuation of statistical and mathematical analysis. The design principles introduced by the behavior theorists continue to guide the development of today’s computer-based learning. In distance education courseware and instructional software, key behavior-modification principles are used. For example, a typical course Web site usually states the objectives of the software; uses text, visual, or audio to apply appropriate reinforcers; provides repetition and immediate feedback; uses principles to shape, chain, model, punish, and award the learners; incorporates a scoring system as a part of the system; and provides status of the progress of the learner.