This study tests the hypothesis that individual differences in locus of control orientation may mediate elementary school students' responses to positive verbal feedback. A total of 30 kindergarten through fourth grade subjects were assessed for locus of control orientation using the Bialer Children's Locus of Control Questionnaire. To establish a baseline measure of initial intrinsic interest, the students were randomly ordered and individually observed during a 10 minute free-choice session in which they were free to engage in various cognitive learning activities. Verbal praise treatment subjects then spent two 30 minute sessions working on a target activity. Children were asked to write down and/or draw pictures of everything that they did. During these work periods subjects individually received positive verbal feedback statements. Subsequently, a post-test session identical to the free-choice pre-test was conducted. Time spent at the target activity during the post-test was the dependent variable. Verbal praise acted to increase intrinsic motivation for subjects higher on internal locus of control. For individuals lower in locus of control verbal praise appeared to decrease motivation. For individuals with an external locus of control orientation, it appears that verbal praise given in support of individual performance on intrinsically motivated tasks may actually reduce intrinsic motivation when that praise is no longer forthcoming. (Author/RH)