Heightened attention to bullying in research and in the media has led to a proliferation of school climate surveys that ask students to report their level of involvement in bullying. In this study, the authors reviewed the challenges associated with measuring bullying and the implications they have on the reliability of school climate surveys. Then they used data from a sample of 810 students in a large public high school in New Jersey to evaluate the merits of using a more generalized definition of aggression in school climate research. Similar to national surveys of bullying, the authors found that boys were more likely than girls to be involved as aggressors, victims, and victim-aggressors for verbal aggression, physical aggression, threats, and damage to property. Girls were more likely to be involved in social aggression. Few differences were observed in aggressive behaviors by grade, but grade level moderated the differences by gender for all types of aggression. The findings demonstrate what school social workers can expect to learn about school climate by using a survey instrument to measure the prevalence of specific categories of aggression that do not include the requisite power differential, a minimum duration of victimization, or an intentionality test.