Aló and Cançado’s (this issue) primary argument is that motivation should be described in terms of an intervening variable. Furthermore, they raise secondary points concerning the status and usage of technical terms and the scope of the motivational concept in behavior analysis. We agree with Aló and Cançado that a clear definition of motivation is essential. However, we disagree with their analysis on a number of fundamental points, such as the correct use of technical terms, the range of phenomena that should be considered as motivational, and we argue that the concept of the intervening variable is incompatible with radical behaviorism. We contend that motivation is best conceptualized as factors that influence the rate of operant responding but that are not part of the operant contingency and that, as with the term reinforcement , the terms operation and process are useful distinctions that should be employed. Key words: motivation, consequence- valuing operation, consequence- valuing process, intervening variable