In 2018, the elementary school where I serve as an instructional interventionist adopted a data-based multi-tiered system of supports (MTSS). Although our process has evolved over the years, I saw room for improvement. Therefore, the purpose of this action research study was to improve the MTSS process at my school, specifically by addressing teachers' lack of awareness of their role. Framing the study with a combination of social cognitive theory and curriculum ideologies, I explored 12 English language arts teachers' perceptions of the MTSS model, curricular views, and sense of self-efficacy. Through a two-phase, mixed-method approach, I investigated how sharing the teachers' collective data impacted their perceptions. The findings of this study indicate that sharing data with teachers created an open dialogue leading to problem-solving, collaborative support, and action plans. Following this small-scale study, the next step is to expand the study to a larger scale and provide ongoing professional development to teachers. [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.]