Reviewing a number of research studies, Johnson (2009) identified items that were associated with lower rates fo school violence. These include positive relationships between teacher and students, fair school rules that are accepted by the students, student "ownership in the school" (p.463), positive school and classroom environments with a focus on "student comprehension"(p.463), and "school safety interventions that are focused on improving the physical environment of the school"(p.463). Litter, graffiti, and general disrepair of the school were often linked to increased violence.