PRIME Technical Report 1: The Development and Validation of the Computer Science Concepts Assessment for Undergraduate Students (UG-CSCA): Preliminary ResultsReportThe Undergraduate Computer Science Concept Assessment (UG-CSCA) is intended to assess STEM undergraduate students’ understanding of basic computer science and programming concepts – variables, conditionals, loops, and algorithms. The validation process of this assessment was guided and informed by a Focal Knowledge, Skills, and Abilities (FKSAs) Framework proposed by Grover and Basu (2017) and the K-12 CS Framework (K–12 Computer Science Framework, 2016). Block-based programming is used as the context for each item in the UG-CSCA. Several studies suggest that block-based programming is effective and appropriate computer programming for novices (Grover, Pea, & Cooper, 2015; Weintrop & Wilensky, 2015), and thus aligns with the intention of this assessment. The current version of the UG-CSCA was written for undergraduate students who are novices in computer science and programming. We believe that this assessment will be useful to instructors who teach introductory computer science and programming courses, as well as computer science education researchers. The instrument was designed for use in pre-intervention-post or longitudinal contexts, as well as for a diagnostic tool. We suggest providing 30-35 minutes for students to complete the assessment which consists of 26 multiple-choice questions.