Discipline referrals and suspensions are used as a last resort to address inappropriate student behavior in schools. The problem investigated in this study was the inconsistent trend in the number of discipline referrals and suspensions during implementation of three different discipline policies (zero tolerance, progressive discipline, and restorative practice) at a local Title I high school in north Texas from 2013 to 2019. Guided by Skinner's theory of behaviorism, the purpose of this quantitative, ex post facto study was to determine if significant differences in the total number of disciplinary referrals and suspensions existed between the 2-year implementation period of each discipline policy. Using the census of school-wide discipline data, differences in total number of discipline referrals and suspensions during implementation of each of the three different discipline policies were tested while controlling for students' GPA. ANCOVA analyses revealed that differences in discipline referrals were not significant (p = 0.403). For suspensions, significant differences were found for zero tolerance compared to progressive discipline and restorative practice (p = 0.000); however, these results need to be interpreted with caution due to violations of assumptions. Findings suggest that continuous monitoring of discipline data should be conducted as a necessary step toward refining discipline policy and practice at the school level. With enhancement of discipline data monitoring, positive social change may occur by fostering better-quality school discipline policy and practice, which may have a positive influence on student achievement, social-emotional wellbeing, and campus climate over time. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]