BRIEF REPORT The SSIS SEL Brief Scales–Student Form: Initial Development and Validation Christopher J. Anthony University of Florida Stephen N. Elliott Arizona State University James C. DiPerna and Pui-Wa Lei The Pennsylvania State University The SSIS SEL Brief Scales–Student Form (SSIS SELb-S) was developed to create an efficient assess- ment of students’ social and emotional learning (SEL). Using item response theory with ratings from 800 students in Grades 3–12 from the standardization sample, 20 items were selected from the full-length SSIS SEL Rating Form - Student to maximize score information and rating efficiency. After identifying items for the SSIS SELb-S, we conducted several reliability and validity analyses. These analyses provided initial support for the use of the SSIS SELb-S for low-stakes decision making contexts. As such, the SSIS SELb-S holds promise for incorporating the perspectives of students ages 8 –18 into assessments of their SEL competencies. Impact and Implications There is increasing need for efficient assessments targeting students’ social and emotional learning (SEL) competencies to support school-based SEL programming. To address this need, the current study used advanced psychometric approaches to develop the SSIS SEL Brief Scales - Student Form, a brief version of the prominent SSIS SEL Rating Form—Student. The resulting measure holds promise to extend and support SEL programming and incorporate students’ self-perceptions into the SEL assessment and intervention process. Keywords: social and emotional learning, student self-ratings, item response theory Increasing attention is being paid to supporting students’ social and emotional learning (SEL) skills in schools across the United States and internationally. Among different types of SEL assess- ments, self-report assessments commonly are used and considered “irreplaceable sources of information about children’s views of themselves” (McKown, 2017, p. 323). Indeed, for many SEL and related domains, student self-report is viewed as the most valid source of information because it encompasses emotions and skills to which only students themselves have access (e.g., internalizing concerns; Smith, 2007). Other common SEL competencies to which students have unique insight include understanding and managing one’s thoughts, emotions and behaviors as well as empa- thizing and relating with others (Weissberg, Durlak, Domitrovich, & Gullotta, 2015). Although there are many frameworks that enumerate these and other important SEL domains, one in particular—the framework developed by the Collaborative for Academic Social and Emotional Learning (CASEL, 2012; see Table 1)— has be- come prominent in research and practice as well as highly influ- ential in SEL-focused policy (e.g., Eklund, Kilpatrick, Kilgus, & Haider, 2018). Despite the growing prominence of SEL in general and the CASEL framework in particular, implementation challenges re- main, especially in the area of self-report assessment (McKown, 2017). Although there are several popular student self-report SEL measures, few are aligned with the CASEL framework, and fewer still are well-adapted for applications within multitiered systems of support (MTSS). For example, CASEL recently conducted a re- view of SEL-focused assessments, including 16 self-report mea- sures (CASEL, 2019). Of the reviewed assessments, most either do not assess more than three CASEL domains (rendering them X Christopher J. Anthony, School of Special Education, School Psy- chology, and Early Childhood Studies, University of Florida; X Stephen N. Elliott, School of Social and Family Dynamics, Arizona State Univer- sity; X James C. DiPerna and X Pui-Wa Lei, Department of Educational Psychology, Counseling, and Special Education, The Pennsylvania State University. Correspondence concerning this article should be addressed to Christo- pher J. Anthony, School of Special Education, School Psychology, and Early Childhood Studies, University of Florida, 2-189 Norman Hall, Gainesville, FL 32611. E-mail: canthony@coe.ufl.edu This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. School Psychology © 2020 American Psychological Association 2020, Vol. 35, No. 4, 277–283 ISSN: 2578-4218 http://dx.doi.org/10.1037/spq0000390 277