Secondary public education for students with severe disabilities offers some of the last opportunities for improved social/behavioral skills, activities of daily living, and cognitive/academic instruction. The problem is that thorough descriptions of self-contained classroom ecology and teachers' use of evidence-based strategies are limited. Framed by the theories of Bandura, Skinner, and Vygotsky, the purpose of this qualitative case study was to explore middle and high school teachers' behavior management and instructional strategies for students with significant cognitive disabilities (SCD). The research questions were designed to address the behavioral and instructional management strategies used in secondary self-contained settings for students with SCD. Using chain sampling of 12 secondary teachers of students with SCD in self-contained settings from an urban public school district in Rhode Island, survey, observation, and artifact data were evaluated to determine themes related to under-reporting, over-reporting, and accurate reporting of the usage of behavioral and instructional strategies used. Similarly, themes related to classroom ecology, challenging behavior, and building-level supports revealed similar variation in reporting. Recommendations for future research include continued inquiry into typography of survey responses related to accuracy of reporting, effective pre-service teacher training for students with SCD, and adaptive or functional instructional curricula outcomes for students with SCD. [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.]