Consider the diagram shown below. Assume that 50 people were assigned to each group.Which of the following would result in the best improvement to this design?
A)Increase sample size to 200 per group
B)Use random assignment to place individuals in each group
C)Decrease the time lag between pretest and post-test
D)Restrict the group composition to include individuals of only one gender

Question

Consider the diagram shown below.  Assume that 50 people were assigned to each group.Which of the following would result in the best improvement to this design?
A)Increase sample size to 200 per group 
B)Use random assignment to place individuals in each group 
C)Decrease the time lag between pretest and post-test 
D)Restrict the group composition to include individuals of only one gender

Quizplus · Accepted Answer

Using random assignment to place individuals in each group will ensure that each group has a similar distribution of characteristics and reduces the potential for confounding variables. Increasing the sample size may improve statistical power, but random assignment is the more critical factor in improving the design. Decreasing the time lag between pretest and post-test may also improve the design, but without random assignment, the potential for confounding variables remains. Restricting the group composition to one gender would limit the generalizability of the findings.

Consider the Diagram Shown Below