Measuring Grit Among First-Generation College Students: A Psychometric Analysis Brooke Midkiff, Michelle Langer, Cynthia Demetriou, and A. T. Panter Abstract The concept of grit is of interest in the field of education, particularly as it pertains to persistence to a 4-year college degree. This study offers an IRT analysis of the Grit Scale when used among first-generation college students (FGCSs) as well as recent first-generation college graduates and non-FGCS recent graduates. The Grit Scale was included in surveys administered as part of an array of other research projects within The Finish Line Project—a US Department of Education First in the World grant-funded project that seeks to improve FGCS access to, persistence in, and completion of postsecondary education through rigorous research into various programs and supports for FGCSs. The reliability and validity of the Grit Scale have not yet been analyzed for use with FGCS or overall with students at large, research universities. By comparing enrolled students and recent graduates, the psychometric analysis in this study offers insight into the measurement of student grit for use in program development and policy-making to improve student retention. Item response theory (IRT) analyses, analysis of differential item functioning (DIF), reliability analyses, convergent and discriminant validity analyses, and known groups validity analyses were used to examine the Grit Scale. Keywords Grit • First-generation college students • Item response theory • Differential item functioning 1 Factor Structure and Uses of the Grit Scale The latent construct of grit is reported to be comprised of two elements— perseverance of effort and consistency of interest in the original research into grit (Duckworth et al. 2007). Grit has been shown to be an effective predictor of success and retention in a variety of contexts such as the national spelling bee, military, B. Midkiff () • C. Demetriou • A.T. Panter University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA e-mail: bmidkiff@email.unc.edu; cyndem@email.unc.edu; panter@email.unc.edu M. Langer American Institutes for Research, Washington, DC 20007, USA e-mail: mlanger@air.org © Springer International Publishing AG 2017 L.A. van der Ark et al. (eds.), Quantitative Psychology, Springer Proceedings in Mathematics & Statistics 196, DOI 10.1007/978-3-319-56294-0_35 407 bmidkiff@email.unc.edu