Professor Marshall wants to know whether eating sweets before bedtime causes children to take longer to fall asleep. In his experiment, whether or not a sweet is given before bedtime is the:
A) independent variable.
B) dependent variable.
C) control variable.
D) extraneous variable.

Question

Quizplus · Accepted Answer

The independent variable is the factor that is being manipulated in the experiment, in this case, whether or not a sweet is given before bedtime. The dependent variable is the outcome being measured, in this case, the length of time it takes for the children to fall asleep. The control variable is a factor held constant and not changed throughout the experiment to ensure that any effects observed are due to the independent variable. Extraneous variables are factors that may influence the dependent variable, but are not being manipulated in the experiment. In this case, eating sweets before bedtime is the variable that is being manipulated, making it the independent variable.

Professor Marshall Wants to Know Whether Eating Sweets Before Bedtime