Behavior-behavior analyses are concerned mainly with the prediction of behavior and are thereby insufficient for a complete functional analysis of environment-behavior interaction. Nevertheless, behavior-behavior analyses can remain within the conceptual framework of radical behaviorist epistemology if they are treated as a preliminary strategy for the identification of those environmental variables that control the behavioral interaction itself. The realization that studying behavioral interactions is primarily a heuristic exercise is especially important, because radical behaviorists conducting research on human schedule performance are very often in contact with social contingencies that reward behavior-behavior analysis but very rarely encourage environment-behavior analysis.