Psych 100: Introduction to Psychology
Sue Frantz
Experimental Design
Design an experiment to test ONE of the hypotheses that can be found under the “Experimental Design” section of the Psych 100 website.
Hypothesis:
People will behave more aggressively when drinking alcohol.
Description of your design (10 points):
Forty students from the local college will be asked to participate. Students will be randomly assigned to either drink alcohol (2 twelve ounce cans of beer in 30 minutes) or drink water (2 twelve oz glasses in 30 minutes). Random assignment gives us two groups that look alike. If the two groups are similar in the beginning, any differences we see in the end are due to what they experienced in the experiment.
When the participant leaves the room, another student working for the experimenter will ‘accidentally’ bump into the participant. This incident will be filmed. Films of each interaction will be shown to a completely new group of participants who have no idea of the hypothesis of the study. These participants will be asked to rate the aggressiveness (based on verbal behavior, hand gestures, body posture, etc.) of the participant who was bumped into.
A potential confounding variable is the amount of liquid the participants drank, so I am requiring both groups to drink the same amount.
Another confounding variable is that one group knows they're drinking alcohol and the other group knows they're drinking water. If there is an increase in aggressiveness in the alcohol group, is it because of the alcohol or because the participants think that alcohol is supposed to make them aggressive? We might be able to eliminate this confound by putting vodka on the lip of the water glasses. The smell of the vodka may make those in the water condition think they are drinking alcohol, that way both groups think they're drinking alcohol. Then if we see a difference in aggressiveness, we know it's from actually consuming alcohol and not thinking that one had consumed alcohol.
Independent variable(s) – be certain to identify your experimental and control conditions (5 points):
IV: Intoxication – alcohol (experimental condition) vs. water (control condition)
Dependent variable(s) (5 points):
DV: Level of aggressiveness as rated by people who are not aware of the hypothesis.