For which of the following reasons might a researcher choose a pretest/posttest design?
A) To ensure that random assignment made the treatment/comparison groups equal
B) To determine how groups change over the course of the experiment
C) To avoid selection threats
D) Both a and b
E) All of the above

Question

Quizplus · Accepted Answer

A pretest/posttest design can help ensure that random assignment made the treatment/comparison groups equal by measuring the groups before the treatment begins. Additionally, it allows the researcher to see how the groups change over the course of the experiment, fulfilling the second option. While a pretest/posttest design does not fully eliminate selection threats, it can help to mitigate them to some extent. Therefore, the correct answer is D, as it includes options a and b, but not c or e.

For Which of the Following Reasons Might a Researcher Choose