Colleges and universities are increasingly using national surveys to assess their students' learning and development. Given the importance of the first year of college for student adjustment and retention (Tinto, 1993), some of these surveys are designed specifically to gauge the experiences and outcomes of first-year students. These large-scale surveys provide valuable information for higher education researchers, administrators, and practitioners. However, a growing body of research has questioned the validity of the measures of student self-reported gains in learning and development that are frequently employed in these assessments (Bowman, 2010a, 2010b, 2011; Bowman and Brandenberger, 2010; Pascarella, 2001; Pike, 1993, 1999; Porter, in press). To date, there is surprisingly little evidence that suggests self-reported gains accurately reflect college students' growth. Importantly, as the authors will show in this study, students' errors in judgment often reflect systematic biases that are largely predictable, so a better understanding of the biases in self-reported gains may ultimately help universities assess their students' learning and development more accurately. This paper explores the validity and potential biases of college self-reported gains among first-year and more advanced undergraduate students, with a focus on social desirability bias and a generalized disposition toward reporting gains. (Contains 4 tables.)