Families in the United States and worldwide are undergoing rapid changes owing to large-scale social and economic trends. Demographic shifts, economic upheavals, changing societal norms and values, and both immigration across national borders and migration within nations are creating new and altered structures, processes, and relationships within families. In response to these changes in the contexts and nature of the family, the science of research on families is on the brink of a new and exciting integration of methods, disciplines, and epistemological perspectives. The methods used to study families are becoming more wide ranging, and both senior and junior scientists are combining approaches from a variety of disciplines. No single research methodology can master the complexity of the family. Demographic data are invaluable but can be limited by a lack of understanding of new family processes. Qualitative data can provide an essential complement to quantitative data but can be limited in estimating large-scale patterns. Assessment of physiological, biological, and epigenetic processes is increasingly being integrated into family research, but these multidisciplinary and multimethod studies often require greater emphasis on team building and long-term approaches. A strong interest in better understanding how scientific research on the family can be used to improve the health and well-being of children has spawned a large and growing body of data from various disciplines. The new science of family research cuts across many disciplines: demography, anthropology, psychology, sociology, economics, education, genetics, neuroscience, and developmental biology. Researchers from these fields use case studies, ethnographies, longitudinal studies, diary and time use records, assessments, administrative records, biological and genetic assessments, and many other methodologies. The results are theories and hypotheses that reflect many different disciplinary perspectives.