The gap between scientific knowledge and real world practice continues to be a major conundrum for the behavioral sciences. This paper briefly reviews the development of behavioral research and describes problems that have arisen in meeting the goal of improving behavioral interventions through science. Based on published literature and personal observations, the authors argue that behavioral research has followed too closely after the pharmaceutical research model, with reliance on small efficacy trials under optimal conditions. Specific problems are outlined along with three recommended solutions. In brief, real world feasibility testing is essential, and external validity must become as important as internal validity for evidence of effectiveness. (Contains 1 figure.)