This mixed-methods case study explores the establishment, change, and sustainability of grading practices among high school teachers. Through Q-methodology, this study investigates teachers' perspectives on grading, their motivations for adopting alternative practices, and the challenges they face in implementation. The study's findings reveal that teachers primarily rely on personal experience and limited training to develop grading practices. Social networks among teachers can play a crucial role in influencing the adoption of alternative grading practices. Additionally, collective leadership and professional development can help foster a culture of innovation and support for change. However, resistance to change and the dominance of traditional practices remain significant challenges. [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.]