Chapter 6.2, Problem 6.33E

(a)

To determine

To explain why will we use as the response variable to measure change in depression after treatment.

Explanation of Solution

The Beck Depression Inventory would be the response variable, since it provides a numerical value for the severity of depression.

(b)

To determine

To outline the design of a completely randomized clinical trial for the study.

Explanation of Solution

110 patients are randomly assigned to each of the three treatments: St. John's Wort, the placebo, and Zoloft. All patients will be assessed with the Beck Depression Inventory before given the treatment. The patients will then be given their assigned treatment. After a designated period of time on the treatment, the patients will be reassessed with the Beck Depression Inventory again.

The outline is as;

  

(c)

To determine

To explain what other precautions would you take in this trial.

Explanation of Solution

The other precautions we should take is that it is important that the patients do not know which treatment that they have been given.