The systematic differences between the control and treatment groups can be controlled by taking two years data, _____.
A)one treatment group before policy change and one after the change
B)one before the policy change and one after the change
C)one control group and one treatment group
D)one control group before policy change and one after the change

Question

The systematic differences between the control and treatment groups can be controlled by taking two years data, _____.​
A)​one treatment group before policy change and one after the change
B)​one before the policy change and one after the change
C)one control group and one treatment group
D)​one control group before policy change and one after the change

Quizplus · Accepted Answer

By taking data from one year before the policy change and one year after the change in both the control and treatment groups, any systematic differences that may exist between the two groups can be accounted for and controlled. This will provide a more accurate assessment of the impact of the policy change. Option A is not correct because it only includes one treatment group and provides no comparison to a control group. Option C is not the best choice as it does not account for the changes over time. Option D may result in uncontrolled factors that may bias the results.

The Systematic Differences Between the Control and Treatment Groups Can