Describe the fundamental flaw that prevents a nonequivalent group ...

[deesands]

Describe the fundamental flaw that prevents a nonequivalent group design from being a true experiment. (That is, why can't these designs produce an unambiguous cause-and-effect explanation?) Explain how the pretest scores in a pretest-posttest nonequivalent control group design help reduce this problem.
 
  What will be an ideal response?

Question 2

What social threat to internal validity occurs when the control group is given a program or treatment (usually by a well-meaning third party) designed to make up for the treatment the program group receives?
 
  a. diffusion of treatment
 b. compensatory rivalry
 c. resentful demoralization
 d. compensatory equalization

[Brenm]

Answer to Question 1

The basic flaw with a nonequivalent group design is that there is no assurance that the different groups in the study were equivalent before the treatments were administered. As a result, there are always two possible explanations for any differences that may be found between treatments: the differences may be caused by the treatments or the differences may have existed before the treatments were introduced. This problem is reduced by the pretest measurements in a pretest-posttest nonequivalent control group design. If the two groups have similar pretest scores, then you have some assurance that the two groups are equivalent, at least for the variable being measured.

Answer to Question 2

d

[deesands]

Thank you

[Brenm]

No problem