The purpose of this mixed-method action research study was to improve Black students' performance in my sixth-grade science class by improving their ability to use the claim, evidence, and reasoning (CER) framework. Using criterion-based convenient sampling, I enlisted 17 Black participants, all of whom were underperforming in my science class at a suburban, middle-class, predominantly White public middle school serving Grades 6-8. As a teacher researcher, I implemented and assessed an intervention designed to improve their ability to use the CER framework. Using a mixed-method action research design, I simultaneously collected and triangulated quantitative and qualitative data. This study may inform future studies or provide insights into solving similar problems at my middle school or other schools in the district. Teaching CER skills to Black students to improve their science performance allowed me to improve my pedagogy through this action research cycle. I gained new knowledge to apply to my immediate teaching and learning process in my classroom or science department. My colleagues can also benefit from my findings and use them to support their teaching. [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.]