A small pilot study is run to compare a new drug for chronic pain to one that is

currently available. Participants are randomly assigned to receive either the new

drug or the currently available drug and to report improvement in pain on a 5-point

ordinal scale: 1 = Pain is much worse, 2 = Pain is slightly worse, 3 = No change, 4 =

Pain improved slightly, 5 = Pain much improved. Is there a signiWcant difference in

self-reported improvement in pain? Use the Mann-Whitney U test with a 5% level of

signiWcance.

New Drug: 4 5 3 3 4 2

Standard Drug: 2 3 4 1 2 3