The purpose of this study was to investigate the effects of choice and environmental control on perceived control. A paired associate choice task was presented to all subjects and they were allowed to choose the response terms to be learned. When each of the response words was chosen aloud, the screen on which the words were printed went blank in the 100% implicit control and 100% explicit control groups. In the latter group, the subjects were informed a priori that the words would be removed from the screen, while in the no-control group, the screen did not go blank when the subjects responded. In the 50% implicit control and 50% explicit control groups, the screen went blank upon responding on a random half of the decision trials. Half of the subjects received an uncontrollable continuous white noise (90 dB) throughout the decision trials, while no noise was presented to the remainder. Upon completion of the choice task, subjects were presented with a dice game, which measured the generalized effects of perceived control. The relationships between environmental control and perceived control were different in the explicit control and implicit control conditions. In the presence of noise, environmental control produced an increment in the perception of control. Finally, consistent environmental control produces greater perceived control than does random control. The motivation model and applications of environmental control were discussed. / Ph. D.