The AARP Bulletin (March 2010) included the following short news brief:“Older adults who did 1 hour of tai chi twice weekly cut their pain from knee osteoarthritis considerably in a 12-week study conducted at Tufts University School of Medicine.” Suppose you were asked to design a study to investigate this claim. Describe an experiment that would allow comparison of the reduction in knee pain for those who did 1 hour of tai chi twice weekly to the reduction in knee pain for those who did not do tai chi. Include a discussion of how study participants would be selected, how pain reduction would be measured, and how participants would be assigned to experimental groups.