Despite major advances in understanding the impact of bullying, its impact on children, and interventions, assessment practices do not appear to adequately measure all of the complex interactions involved with bullying victimization. Bullying assessment can be enhanced by systematically including all core bullying behaviors, more thoroughly examining sources of power differential between bullies and victims, and giving more attention to the dynamic nature of the bullying process. The quality of understanding of youth experiences with bullying and peer victimization hinges on the ability to effectively assess these constructs. Over the years, various assessments have been proposed to measure bullying. Bullying is a specific type of peer victimization and, as such, requires special attention to measurement. This paper examines the conceptual basis for and methods used to assess school bullying, including the core bullying behavior elements of repetition, intentionality, and power differential and instruments needed to foster comparability across studies and improve the precision of intervention capacity. Table, notes, and references