Theories about, methods of studying, and definitions of family have undergone profound shifts over the last several decades, and change continues to characterize developmental research on family functioning. In the 1990s, researchers have recognized the need for more descriptive studies as well as more process-oriented work. Research is beginning to integrate knowledge of biological, affective, social, and cognitive processes in families into multi-process frameworks, with the goal of developing models that capture the variability and richness of these processes in different types of families. Sampling strategies have also changed, leading to an increased interest in large, representative national samples. The study of families will likely become an increasingly interdisciplinary enterprise in which sociologists, demographers, anthropologists, psychologists, historians, and psychologists all play a role. (MM)