The independent variable in this experiment is the amount of alcohol.
The dependent variable in this experiment is the reaction time of the responses of the subjects during the video game.
Operational definition of independent variable:
Alcohol is known to be a psychoactive drug that slows the faculties of cognition and perception. Thus, it would interfere with the reaction time of the subjects during the experiment.
Your professor has designed a research study to examine the effects of alcohol on reaction time....