as a measure of motivation in this experiment. Absences were used as a measure of attitudes. To assess the stability of the observed effect, the experimenter observed the students again (Time 4) for two weeks. There was a gap of five weeks between Time 3 and Time 4. Due to absences and change in assignment etc., motivation data was not available for all students. The results of this experiment were similar to Experiment I and monetary reward was found to decrease the intrinsic motivation of the students, supporting Deci's hypothesis. Experiment III Experiment III was also conducted in the laboratory and was identical to Experiment I in all respects except for the kind of external reward provided to the students in the experimental condition during Session 2. In this experiment, verbal praise was used as an extrinsic reward. The experimenter hypothesized that a different type of reward—i.e., social approval in the form of verbal reinforcement and positive feedback for performing the task that a person is intrinsically motivated to perform—enhances the degree of external motivation, even after the extrinsic reward is removed. The results of the experiment III confirmed the hypothesis and the students' performance increased significantly during the third session in comparison to session one, showing that verbal praise and positive feedback enhances performance in tasks that a person is initially intrinsically motivated to perform. This provides evidence that verbal praise as an external reward increases intrinsic motivation. The author explained differences between the two types of external rewards as having different effects on intrinsic motivation. When a person is intrinsically motivated to perform a task and money is introduced to work on the task, the individual cognitively re-evaluates the importance of the task and the intrinsic motivation to perform the task (because the individual finds it interesting) shifts to extrinsic motivation and the primary focus changes from enjoying the task to gaining financial reward. However, when verbal praise is provided in a similar situation, it increases intrinsic motivation as it is not evaluated to be controlled by external factors and the person sees the task as an enjoyable task that is performed autonomously. The increase in intrinsic motivation is explained by positive reinforcement and an increase in perceived locus of control to perform the task. Pritchard et al. (1977): Evaluation of Deci's Hypothesis Pritchard et al. conducted a similar study to evaluate Deci's hypothesis regarding the role of