Sixty-four 4th graders were subjects in this experiment which examined children's choice behavior under conditions of uncertainty. In the experimental condition, 2 rewards were offered, one of which was concealed by a question mark. In addition the question mark concealed one of 2 possible rewards, presented according to varied probability schedules. To the subjects, it was uncertain what was under the question mark. The control condition contained no such uncertainty, since the question marks were colored and associated with a specific, known reward. Findings indicate that children chose the question mark more frequently in the experimental condition than in the control condition. Other findings are also reported which suggest that the desire to reduce uncertainty is not the only variable operating, but that the value of the reward influences choice as well. The data points to the incentive properties of uncertainty reduction, or information, for children. Implications for learning are touched upon in the discussion. (TL)