With over 30 years of proven efficacy our multitiered approach has helped school districts throughout North America build the knowledge base needed to create these positive school environments that are emotionally and physically safe and that foster independence, integrity, confidence, self-control, kindness, and responsibility.
The graphic below shows the three levels as an inverted triangle with schoolwide procedures at the top.

students need extra support in the classroom,develop individualized
plans as necessary
large numbers of students are having trouble in their classrooms,targeting classroom 
procedures is indicated.
large numbers of students are misbehaving across school settings,modifying schoolwide procedures
is the best intervention.
large numbers of students are requiring individualized plans,staff need to focus more time,
effort, and energy on schoolwide and classroom procedures.