Eric Mash is a professor of psychology at University of Calgary in Canada, where he enjoys teaching undergraduate classes in abnormal child psychology, behavior modification, and developmental psychopathology as well as graduate classes in clinical psychology, specifically in child psychopathology, child assessment, and child psychotherapy. He earned his Ph.D. in clinical psychology at Florida State University, and completed his residency in clinical child psychology at Oregon Health and Sciences University in Portland, Oregon. Eric commits much of his time and energy outside of the classroom to researching the topics of abnormal child psychology, child and family assessment, child psychotherapy, and child development. Particularly interested in attention-deficit disorder and conduct problems, and in families in which children have been physically abused, Eric has contributed and published many journal articles and books on these topics. He is also a Fellow of the American and Canadian Psychological Associations, and has served on the editorial boards of many prestigious journals and grant agencies at local and federal levels. David Wolfe is the first recipient of the RBC Investments Chair in Developmental Psychopathology and Children's Mental Health at the Centre for Addiction and Mental Health, University of Toronto, and the Academic Director of the Center for Research on Violence Against Women and Children. He enjoys teaching abnormal child psychology, child assessment and psychotherapy, and community psychology to undergraduate students. He earned his Ph.D. at University of South Florida in Tampa, and completed his residency in clinical psychology at University of Mississippi Medical Center. David is a founding member of the Center for Research on Violence Against Women and Children, and also a fellow of the American Psychological Association (APA), where he served as president of Division 37, Child, Youth, and Family Services. He lends special focus to child abuse, domestic violence, and development and developmental psychopathology, as well as the impact of early childhood trauma on later development in childhood, adolescence, and early adulthood. Currently David focuses attention on studying ways to prevent violence in relationships with adolescents.