If you were designing the study referred to in Exercise 18.1, what else would you like to

Question:

If you were designing the study referred to in Exercise 18.1, what else would you like to have collected to clarify the meaning of your results?

Exercise 18.1

Migraine headaches are a problem for many people, and one way of treating them involves relaxation therapy. A study of the effectiveness of relaxation techniques in the treatment of migraines was conducted by Blanchard, Theobald, Williamson, Silver, and Brown (1978). The data that follow are in agreement with those found by Blanchard et al. (Their study was more complex than the one examined here.) I have calculated to save you work. image text in transcribed