2.34 A study of college students showed a temporary gain of up to 9 IQ points after listening to a Mozart piano sonata. This conclusion, dubbed the Mozart effect, has since been criticized by a number of researchers who have been unable to confirm the result in similar studies. Suppose that you wanted to see whether there is a Mozart effect for students at your school. (Hint: See Examples 2.4 and 2.5.)

a. Describe how you might design an experiment for this purpose.

b. Does your experimental design include direct control of any extraneous variables? Explain.

c. Does your experimental design use blocking?
Explain why you did or did not include blocking in your design.

d. What role does random assignment play in your design?