This handbook gives researchers and students an overview of the rich history of methodological innovation in both basic and applied research within social psychology. It is sometimes difficult for researchers, new and seasoned alike, to keep up with innovations that allow a greater diversity in the kinds and levels of research questions that can be addressed. As a result, the nature of the questions asked by many researchers may be unnecessarily constrained. Conversely, a rush to embrace newer approaches can lead to less-than-thorough consideration of fundamental issues that transcend any particular approach. The editors believe that the decision to use a particular methodological approach is optimally made when grounded in careful consideration of the `big picture' of a program of research. Thus, methodological decisions are inextricably tied to what the researcher, ultimately, wants to know. In other words, research questions guide the methods rather than the reverse. Based on this `top-down' perspective, chapters in this volume emphasize the conceptual basis of the methodology, with an explicit focus on the meaning of data when obtained via a particular methodology.