Question

The effect of the time of day a psychology class is taught on test scores is being studied in an experiment. The difficulty of test questions has been identified as an extraneous factor that could also affect test scores. How can the difficulty of test questions best be addressed to minimize its effect in the experiment?

A. Implementing direct control by requiring every class to take the same test with varied difficulty levels.
B. Grouping into sets based on the test difficulty and assigning them randomly to classes.
C. Adjusting the difficulty based on the time of day each class is scheduled.
D. Balancing the difficulty by creating multiple versions of the test and randomly assigning them to different classes

Answer 1

The correct option is D. Balancing the difficulty by creating multiple versions of the test and randomly assigning them to different classes

To address the effect of test difficulty on scores in an experiment about class time and test performance, creating multiple test versions and randomly assigning them to classes is the best approach for balancing difficulty levels.

Step-by-step explanation:

To minimize the effect of the difficulty of test questions in an experiment studying the effect of the time of day a psychology class is taught on test scores, the best approach would be Balancing the difficulty by creating multiple versions of the test and randomly assigning them to different classes (option D).

This method ensures that each class has an equal chance of receiving a test of any given difficulty level, removing the difficulty as a confounding variable. By contrast, options A and C introduce more variability and potential biases, and option B does not specify how the tests' difficulty levels would be balanced between the classes.

Moreover, random assignment is a key practice in experimental design, as it helps ensure that any potential lurking variables are evenly distributed across all the groups, thereby giving a clearer picture of the true effect of the independent variable, which, in this case, is the time of day the class is being taught.