This collection brings together literature to inform researchers about the many issues that have influenced and continue to refine the use of experimental designs in the behavioral and social sciences. The collection includes articles, primarily from scholarly journals, that highlight perspectives of recognized leaders on historical, theoretical, methodological, and pragmatic considerations affecting the role of experimental designs within the behavioral and social sciences. The selected articles are problem-focused, include illustrative examples and provide comprehensible input for a broad audience spanning multiple disciplines.