Legitimate knowledge claims about causation have been a central concern among evaluators and applied researchers for several decades and often have been the subject of heated debates. In recent years these debates have resurfaced with a renewed intensity, due in part to the priority currently being given to randomized experiments by many funders…

"Theory as Method: Small Theories of Treatments," by Mark W. Lipsey, is one of the most influential and highly cited articles to appear in "New Directions for Evaluation." It articulated an approach in which methods for studying causation depend, in large part, on what is known about the theory underlying the program. Lipsey discussed the benefits…

Education researchers, practitioners, and policymakers alike are committed to identifying interventions that teach students more effectively. Increased emphasis on evaluation and accountability has increased desire for sound evaluations of these interventions; and at the same time, school-level data have become increasingly available. This article…