Selection differences in the nonequivalent control group design are:
A)essential to the design because they enhance the independent variable.
B)essential to the design because they allow greater differences than the dependent variable.
C)problematic because they challenge the external validity of the study.
D)problematic because they challenge the internal validity of the study.

Question

Quizplus · Accepted Answer

Selection differences in the nonequivalent control group design can threaten the internal validity of the study because it is difficult to determine whether the differences observed between the groups are due to the independent variable or to the pre-existing differences between the groups. Therefore, it is important for researchers to carefully match the groups on relevant variables as much as possible or to use statistical techniques to control for potential confounders in the analysis.

Selection Differences in the Nonequivalent Control Group Design Are