This page includes data from the Wisconsin Department of Public Instruction and the U.S. Centers for Disease Control and Prevention (CDC) on weapons at school. The Youth Risk Behavior Surveillance System (YRBSS) survey asks high school students to report if they have carried a gun on school property in the past 30 days or if they have been threatened with a weaponon school property in the past year. The YRBSS is administered by the Wisconsin Department of Public Instruction in conjunction with the CDC. The vertical gray lines in the graphs reflect a change in methodology from paper survey to online survey. This change could impact the makeup of the groups responding to the survey. In addition, the question concerning carrying a gun to school changed. It was formerly carrying a weapon of any type within the past year; it is currently carrying a gun within the past 30 days. Restraint should be used when making yearly comparisons across this boundary line.