Matthew is conducting research to learn whether chewing peppermint gum during learning will improve recall if the participants are also chewing peppermint gum when they take a test.Matthew assigns the first 10 people who arrive to his experimental group.He assigns the last 10 people to his control group.What mistake has Matthew already made?
A) He didn't ask if anyone prefers cinnamon gum.
B) He forgot to ask how old each of the subjects is.
C) He failed to use random assignment.
D) He forgot that food (including gum)is always confounded.

Question

Quizplus · Accepted Answer

Matthew failed to use random assignment, which means that there is a chance that the two groups may differ in important ways before the experiment even begins. This can affect the validity of the results and make it difficult to determine the true cause of any differences in recall between the two groups.

Matthew Is Conducting Research to Learn Whether Chewing Peppermint Gum