The randomized research study assessed the effect of an inquiry-based science (IBS) program on non-cognitive outcomes and academic achievement. The study was the result of a grant that was awarded by Professional Resources in Science and Mathematics (PRISM), a program affiliated with Montclair State University in conjunction with Bristol-Myers Squibb, and part of the New Jersey Statewide Systemic Initiative (NJSSI). The NJSSI is a partnership of schools, districts, colleges and universities, science centers, businesses, and museums dedicated to improving the teaching and learning of science, mathematics, and technology in New Jersey. The quantitative research study utilized an IBS instructional program titled Science and Technology Concepts for Middle Schools (STC/MS) and was implemented in two middle schools within the same suburban school district. This study examined the effect of IBS classrooms on learning outcomes specifically related to gender and special education. Evaluation of student learning outcomes was conducted through the administration of three instruments: the Academic Self-Concept (ASC) scale, unit assessments, and NJASK 8 Science. The ASC scale and unit assessments were administered as a pretest and posttest in IBS classrooms. NJASK 8 Science scale scores were obtained through reporting of student performance data from the New Jersey Department of Education to the district. The quantitative analysis in this study provided evidence that IBS classrooms had a positive effect on academic achievement. Overall, students in IBS classrooms performed better than students in traditional classrooms on unit assessments. Additionally, male students and special education students in IBS classrooms outperformed students in traditional classrooms on unit assessments. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]