Criticisms of the use of experiments and quasi-experiments in the evaluation of juvenile treatment programs have been presented extensively and forcefully by Hackler, who reviewed a wide variety of evaluation projects, particularly that of the Opportunities for Youth Project in Seattle. Hackler notes that evaluations based on experimental methodologies tend to show that nothing works in the treatment of juvenile delinquency. He warns researchers to avoid experimental methodology because it usually results in the demise of innovative and humanistic programs. However, this view is unwarranted, as is the view that nothing works in the treatment of delinquents. Although researchers must consider many practical and valid issues in deciding whether to use experiments, they should recognize that this approach remains the most powerful evaluation methodology available. The wide array of treatment programs in existence represent a variety of theoretical perspectives. Experiments can provide an assessment of competing theories. Researchers need to work toward development of a systematic and practical evaluation methodology. Despite the existence of the view that nothing works in juvenile treatment, little systematic dismantling of juvenile treatment programs has occurred, perhaps because few politicians are willing to abandon a humanistic policy toward juveniles. Experimental criteria will aid the evaluation of juvenile programs by raising the standard evidence required before policymakers will make major changes in the juvenile treatment system. One note and 26 references are listed.