I am stuck on these questions:

1. Molly's study examines the benefits of exercise on weight loss. In one group she advocates exercise as well as a new diet program. In the comparison group she only presents the diet program. Those in the comparison group find out that some of Molly's clients are in an exercise program too, so they form an exercise group. This is an example of

A. placebo effect

B. compensatory rivalry

C. experimenter effects

D. treatment diffusion

2. Given the following notation, which design is illustrated?

O X1 O O X2 O

A. Static group comparison design

B. Posttest-only control group design

C. Pretest-posttest control group design

D. Nonequivalent control group design

3. The criterion variable in a prediction study is the name for

A. the independent variable

B. the variable used to select participants

C. the variable that is predicted

D. the variable used to make a prediction.