"There are relatively few guides for researchers who explore the interdependence of human functioning… This book will clearly rectify that limitation… This book... [is] …of great value to many psychologists… [and] for doctoral seminars in developmental psychology or biostatistics...I highly recommend this book." -Theresa Thorkildsen, University of Illinois, Chicago"In its groundbreaking translation of multiple methods to its topic, this is a very important book for those who conduct developmental research on dyads and other interdependent groups. The book is essential for those planning to study development in dyadic or group relationships. As the authors cogently argue, to fail to account for change in the study of relationships is to misunderstand relationships, while the failure to account for relationships in the study of change just as reliably results in a failure to understand change. Thus, the book positions itself to guide researchers in a direction essential for the field of developmental psychology." - Clifton R. Emery, PsycCRITIQUES