Assume that you have developed a study technique that you believe will result in students scoring higher on research methods exams.You test your study technique with the design diagramed below. R=random assignment O=observation X=stimulus
R O1 X O2 R O3 O4
Using the diagramed design,what predictions are correct?
A)O2 should be greater than O1
B)The (O2-O1)change should be greater than the (O4-O3)change.
C)O4 must equal O3
D)All of these choices are appropriate predictions
E)O2 should be greater than O1 and the (O2-O1)change should be greater than the (O4-O3)change

Question

Quizplus · Accepted Answer

The design is a pretest-posttest control group design with random assignment. O1 and O2 are the pretest and posttest measures for the experimental group who receives the stimulus (X). O3 and O4 are the pretest and posttest measures for the control group who does not receive the stimulus.
 
Prediction A (O2 should be greater than O1) is a correct prediction because O2 represents the posttest measure, and if the study technique is effective, the scores should increase from pretest (O1) to posttest (O2).
 
Prediction B (the (O2-O1) change should be greater than the (O4-O3) change) is also a correct prediction. This is because the change in the experimental group (O2-O1) represents the effect of the study technique, whereas the change in the control group (O4-O3) represents any confounding variables or natural variability in the scores. Therefore, if the technique is effective, the change in the experimental group should be greater than the change in the control group.
 
Prediction C (O4 must equal O3) is not a correct prediction because O3 and O4 are the pretest and posttest measures for the control group, and there is no expectation that these scores will be equal.
 
Therefore, the correct prediction is E: O2 should be greater than O1 and the (O2-O1) change should be greater than the (O4-O3) change.

Assume That You Have Developed a Study Technique That You