Before your child can take part in this study, he/she will have what is called a "screening test of intelligence." This test will help the doctor decide if your child is eligible to take part in the study. In order for a child to participate in the study, he or she has to achieve a score > 70 on the screening test (at least within the borderline range of intelligence), because this level of intelligence is necessary for a child to understand the CPT educational materials. It is possible that after this test, your child may not be able to continue on this study. The screening test results will be discussed with you.