Modern eff orts to evaluate bullying prevention programs in schools originated with Dan Olweus and his seminal work in Norway in the early 1990s (Olweus, 1991a, b, 1992a, b, 1993a, b, c, d). Despite increasing attention to the problem of bullying behavior in the United States and the widespread use of bullying prevention programs, there is still a shortage of rigorously designed intervention evaluation studies that can be used to guide prevention eff orts (see Ryan & Smith, 2009, for a recent review), making it diffi cult to draw any consensus about the impact of bullying prevention eff orts and the key mechanisms of change. Th e aims of the current chapter are threefold: fi rst, we will provide a description of how we address some of the analytic and design challenges in our schoolrandomized evaluation of Steps to Respect: A Bullying Prevention Program© (StR; Committee for Children, 2001). Second, we will describe baseline data results from the trial, including psychometrics of outcome measures, baseline equivalency between intervention and controls schools, and the characteristics of our student, teacher, and staff samples as they relate to targeted outcomes and mediators. Lastly, we will present fi ndings and implications of diff erences in perceived school environment, bullying behavior, and likelihood of eff ective intervention in bullying incidents between students and staff .