Ability and non-ability traits were examined as predictors of learning, operationalized as the development of knowledge structure accuracy, and exam performance in a semester-long course. As predicted by investment theories of intellectual development, both cognitive ability and non-ability traits were important determinants of learning and exam performance. Mastery goal orientation (the focus on developing competence) was related to learning, but not exam performance. Conscientiousness was positively related to learning and exam performance. Performance-avoid orientation (a focus on avoiding normative evaluations of incompetence) was negatively related to the development of knowledge structure accuracy, but was positively related to exam performance after accounting for knowledge structure accuracy and cognitive ability--suggesting that wanting to avoid failure may be functional for exam performance, but dysfunctional for learning. (Contains 3 figures and 2 tables.)