Please help! A researcher wants to test whether listening to classical music before bed has an effect on a
college student's sleep quality. Identify a potential problem, if any, with each experimental
design. Then describe how you can improve it.

Sixty college students volunteer to listen to classical music every night before bed for one month. Sixty
other college students volunteer to not listen to any music before bed for one month. Each person is
evaluated and it is determined that the college students who listened to classical music had improved
sleep quality