The purpose of this mixed methods exploratory study was to design and validate an instrument Satter's Preservice Educators Social Emotional Competencies Inventory (Satter's PSESEC-I). The 5-point Likert instrument allows preservice educators to self-assess and reflect on instrument items on their abilities to use social emotional learning and competencies within their student teaching instructional practice with a range of 1=never, 2=sometimes, 3=occasionally, 4=most of the time, and 5=always. This study utilized the Center for Reaching and Teaching the Whole Child (2022) Social, Emotional, and Cultural Anchor Competencies Framework, which contains seven specific social-emotional competencies vital for educators. Lewin's (1946) action research theory was used in this study as the theoretical framework because of its close alignment to the naturally collaborative process preservice educators undergo during their student teaching experience with their university supervisor and cooperating teacher. The researcher used Gehlbach & Brinkworth's (2011) six-step instrument development process for survey development and validation, which included (1) literature review, (2) preliminary study, (3) synthesis of literature review and preliminary study, (4) item development, (5) expert review using Lawshe's (1975) content validity ratio and Ayer & Scally's (2017) procedures for item retention and reduction, and (6) cognitive pretesting. The content validity index for the instrument was determined to be 0.912, indicating high instrument validity. After the survey development was completed, a pilot study was conducted with a sample of n=9 preservice educators. Reliability was not able to be established in this study. However, the results from the pilot study indicate that preservice educators do use social emotional learning and competencies within their instructional practice at self-reported high levels. Mode analysis of participants' responses indicated difficulties utilizing the CRTWC (2022) competency "responding constructively across differences," which aligned with results from the preliminary study's novice educator participants. As a result of the findings, recommendations for educational researchers and leaders were made to provide specific, authentic opportunities for students to gain experience with this competency during their preservice education programs, specifically, with opportunities to demonstrate and assess their competency in fieldwork given the role and importance that culturally responsive teaching practices have in education. [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.]