Aresearcher simultaneously investigated learning style and teaching style. students were identified as either visual/concrete learners or verbal/abstract learners, on the basis of a learning style survey. for each type of student, half were taught a statistics lesson using a computer program that included a lot of graphics, while the other half used a computer program with fewer graphics and more verbal material. after working through the program, all students were given a test on statistics. how would you describe the design of this study?