Accurately measuring human behavior in the social environment is key to evaluating the effectiveness of group work practice. This task is often complicated by lack of valid and reliable instruments. Established and useful measures of human behavior can allow social work group workers to increase our ability to accurately assess behavior and attitude changes, using this information to improve our practice. This is the purpose of Approaches to Measuring Human Behavior in the Social Environment, a collection of articles written by social work researchers focused on the development and testing of various measurement tools for specific populations.