This action research study, set in a midwestern high school in the United States, was designed to investigate the impact of implementing equitable grading practices in a first semester ninth-grade biology course. Many grading practices commonly used in classrooms in the United States are subjective, can be used to maintain compliance in the classroom, and do not accurately report what students know and can do. Ideas from Critical Race Theory and Bandura's Self-Efficacy Theory guided this study. Qualitative and quantitative data were collected through pre and post self-efficacy surveys, grading surveys, and semi-structured student interviews, along with quantitative grade data for student participants. A mixed method approach was used to analyze the data. There was a statistically significant difference in student grades between the school districts mandated grading policies and the equitable grading interventions used in this study. There were statistically significant decreases in overall self-efficacy and the psychological states source of self-efficacy for English Language Learners and students not receiving free or reduced lunch. Student responses also indicated a reduction in stress and an increase in feelings of support during the semester due to several of the equitable grading practices. Implications and recommendations for future research based on these findings are discussed. [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.]