Answer :
Answer:
It is time-consuming.
Explanation:
What differentiate pretest-posttest design with other research method is the number of measurement that the researchers have to take throughout the study.
In this type of study, researchers will have to conducting a pre-test before the actual treatment in order to obtain some sort of preset to predict the outcome of the study and another test after the actual treatment to ensure that the measurement is correct. This will make the time needed to finish the whole study become significantly higher compared to other methods.