An experimenter wants to study the relationship between caffeine and reaction time.She assigns participants as follows: Group One receives 50 milligrams of caffeine;Group Two receives 100 milligrams of caffeine;Group Three receives 200 milligrams of caffeine;Group Four receives no caffeine.Twenty minutes later,all participants complete the reaction-time test.In this experiment,what was the dependent variable?
A) amount of caffeine
B) no caffeine
C) reaction time
D) assignment into one of four groups

Question

Quizplus · Accepted Answer

The dependent variable in the experiment is reaction time, as the experimenter is interested in how the amount of caffeine affects participants' reaction times. The independent variable is the amount of caffeine, and the assignment into different groups is the way the independent variable is manipulated. The absence of caffeine in Group Four is simply the control condition, used for comparison.

An Experimenter Wants to Study the Relationship Between Caffeine and Reaction