Virtual reality hypnosis for pain. The International Journal of Clinical and Experimental Hypnosis (Vol. 58, 2010)

investigated using virtual reality hypnosis (VRH) to reduce the pain of trauma patients. Patients reported their pain intensity on the Graphic Rating Scale (GRS) both prior to and one hour after a VRH session. The researchers reported that hypnosis reduced the pain intensity of trauma patients by an average of m = 10 points on the GRS. Suppose you want to test whether trauma patients who receive normal analgesic care (i.e., medication, but no hypnosis) will have a smaller reduction in average pain intensity than the VRH trauma patients.

a. Set up H0 and Ha for the test.

b. Describe a Type I error for this test.

c. Describe a Type II error for this test.