The nonequivalent comparison-group design is a quasi-experimental design in which, for reasons of practicality, we cannot insure that the control and experimental groups are equivalent to each other when the experiment begins. The major interpretational difficulty imposed by this design is:
A) Measuring whether the two groups are different from each other on the posttest
B) Deciding how much each group has gained
C) Determining when enough data points are collected
D) Being sure that any differences between groups at the end of the experiment are due to the independent variable's influence and not due to preexisting group differences

Question

Quizplus · Accepted Answer

The major interpretational difficulty is ensuring that any observed differences between groups at the end of the experiment are due to the independent variable and not preexisting differences, as the groups are not equivalent at the start.

The Nonequivalent Comparison-Group Design Is a Quasi-Experimental Design in Which