Correlations between self-reported learning gains and direct, longitudinal measures that ostensibly correspond in content area are generally inadequate. This chapter clarifies that self-reported measures of learning are more properly used and interpreted as evidence of students' perceived learning and affective outcomes. In this context, the authors supply evidence that social desirability bias in such self-assessments does not constitute a significant concern. Recommendations for use of self-reported gains in research and institutional assessment are discussed. (Contains 2 tables and 1 figure.)