An experimenter wants to find out if drinking coffee makes people more alert. The amount of coffee a person drinks is the:
A. hypothesis.
B. dependent variable.
C. independent variable.
D. correlation coefficient.
The amount of coffee a person drinks is the independent variable because it is the variable that you would be manipulating to find out how that affects alertness which is the dependent variable.
C. independent variable.
The independent variable refers to the factor that is deliberately manipulated or controlled by the experimenter. In this case, it is the amount of coffee a person drinks. The experimenter wants to find out if drinking coffee affects people's alertness. To determine this, the experimenter may assign different amounts of coffee to different groups of individuals or have participants self-report their coffee consumption.
By manipulating the independent variable (amount of coffee), the experimenter can observe and measure the effects on the dependent variable (alertness). The dependent variable is the outcome or response that is being measured or observed, which in this case is people's alertness.