No Child Left Behind Act of 2001 (NCLB) requires the use of scientifically based research (SBR) to guide the selection of appropriate educational interventions. Although NCLB does not stipulate the use of scientifically based research specific to special education, its provisions influence the education of all children. The implementation of scientifically based research is complex and relies on the knowledge and beliefs of practitioners in general and special education. In order to utilize scientifically based research, there is a need to know the level of knowledge and attitudes of practitioners relative to scientifically based research. This study examines the relationship between practitioners' beliefs and actions taken when implementing scientifically based research. The theoretical framework of Argyris and Schön (1974) provides a conceptual framework for the interpretation of the data. Connections between scientifically based research, school leadership, practitioners, and students, including those with disabilities, are also examined. Information and results extracted from survey responses of 403 middle school teachers from a large, urban school district in Texas shed light on how knowledge and beliefs can influence the understanding and the implementation of scientifically based interventions. The results indicate that teachers are somewhat knowledgeable about scientifically based research and interventions. However, their responses to three open-ended questions provide increased insight into their actual knowledge and understanding. The results indicate that initially teachers are in need of more knowledge about scientifically based research and what constitutes quality research. Their responses also indicate that teachers are lacking concise information that would help them understand what makes an effective scientifically based intervention. Teachers could through college or university classes be better prepared to use scientifically based interventions in the classroom. In the classroom, teachers need administrative support, continuous mentoring and coaching, and effective professional development in order to implement interventions with fidelity. Both general and special education teachers need increased knowledge to use scientifically based interventions effectively to increase student learning. / text