A researcher tests four different groups of participants. Each group is given a different dosage of caffeine, and reaction time is measured for each subject. Which of the following is true?
A)dosage level is the dependent variable
B)reaction time is an independent variable
C)the independent variable has four levels
D)the independent variable is a subject variable

Question

Quizplus · Accepted Answer

The independent variable is the dosage of caffeine, and it has four levels because there are four different groups, each receiving a different dosage.

A Researcher Tests Four Different Groups of Participants