Testing a natural remedy Although the law doesn’t require it, we decide to subject Dr. Moore’s Old Indiana Extract to a clinical trial. We hope to show that the extract reduces pain from arthritis. Sixty patients suff ering from arthritis and needing pain relief are available. We will give a pill to each patient and ask them an hour later, “About what percent of pain relief did you experience?”

(a) Why should we not simply give the extract to all 60 patients and record the responses?

(b) Outline the design of an experiment to compare the extract’s eff ectiveness with that of aspirin and of a placebo.

(c) Should patients be told which remedy they are receiving? How might this knowledge aff ect their reactions?

(d) If patients are not told which treatment they are receiving, the experiment is single-blind. Should this experiment be double-blind? Explain.