Kazdin is to be commended for his analysis of some current issues surrounding research and clinical practice. He described many important considerations and variables that impact the execution and usefulness of research. However, a critical conceptual issue was left unaddressed, one that is rarely addressed in these pages or elsewhere. In looking at questions of conditions and treatments, we need to pay attention to what we mean by "conditions." How the clinician or researcher judges whether treatment has been successful depends in large part on his or her sense of the underlying condition being treated.