Two studies were conducted to determine the degree to which various types of power were employed in the classroom and the effects of each type on both cognitive and affective learning. The primary focus of the first study was to determine the degree to which teachers and students shared perceptions of the use of power in the classroom. Power was measured as relative or perceived. A total of 156 teachers and 2,698 of their students provided data. The results indicated that even though statistically significant associations between teacher and student were found, teacher and student perceptions of the use of power were not isomorphic. The results also indicated that both teachers and students viewed the overwhelming proportion of power use to stem from reward, reference, and expert bases. The second study focused on the degree to which use of power in the classroom was associated with cognitive and affective learning. The results, based on data from 151 teachers and 2,603 of their students, indicated that perceived use of power could account for approximately 30% of the variance in cognitive learning and up to 69% of the variance in affective learning. Coercive and, to a lesser extent, legitimate power were found to be negatively associated with learning while referent and, to a lesser extent, expert power were found to be positively associated with learning. Reward power was found to have no meaningful association with learning. (Author/HOD)