Question

Describe how the two-group pretest/posttest design with random assignment might be implemented to determine if people learn from a diabetes education course.

Answer 1

• A two-group pretest–posttest design is an experimental design, which compares the change that occurs within two different groups on some dependent variable (the outcome) by measuring that variable at two time periods, before and after introducing/changing an independent variable (the experimental manipulation or intervention).
• The principle behind this design is relatively simple, and involves randomly assigning subjects between two groups, a test group and a control. Both groups are pre-tested, and both are post-tested, the ultimate difference being that one group was administered the treatment.
• In this case, the researcher conducts pretest for both test group and control group regarding their knowledge on diabetes and gives diabetes education to only test group. After a period of time the posttest is administered to both the groups. Then the researcher analyses the effectiveness of his teaching by comparing the score of both the groups.
• The researcher can see how both groups changed from pretest to posttest, whether one, both or neither improved over time.
• This design allows researchers to compare the final posttest results between the two groups, giving them an idea of the overall effectiveness of the intervention or treatment.
• The researchers can compare the scores in the two pretest groups, to ensure that the randomization process was effective. These checks evaluate the efficiency of the randomization process and also determine whether the group given the treatment showed a significant difference.