Dr. Phillips is a cognitive-developmental psychologist who studies how children learn mathematical principles. His current interest is in studying how children learn multiplication. He recruits 54 second-graders who have not yet learned how to multiply numbers to participate in his study. He is curious as to whether different teaching styles lead to better mastery of the subject. One condition (A) involves having students read a chapter on multiplication from their textbook. One condition (B) involves having stud