The purpose of this study was to examine the effect of the implementation of Schoolwide Positive Behavior Interventions and Supports (SWPBIS) guidelines for success on the academic achievement of students who are at-risk academically and/or behaviorally in a small private school in the southeastern United States. The student population consisted of students with and without disabilities, some of whom require additional academic and behavioral support. The author analyzed results from NWEA's Measures of Academic Progress (MAP) testing to determine the effect of the implementation of SWPBIS guidelines for success on academic achievement in the areas of reading and math. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]