Questions: Elsa is conducting an experiment to find out if caffeine improves driving performance. She randomly assigns participants to drink either 2 cups of regular coffee or 2 cups of decaf coffee, and then measures driving performance on a driving range. The independent variable in Elsa's experiment is driving performance. the group that got regular coffee. the group that got decaf. which beverage people got.

Identify the independent variable in Elsa's experiment.

Definition of independent variable

The independent variable is the variable that is deliberately manipulated or changed by the experimenter to observe its effect on the dependent variable.

Analyze the options

• Driving performance: This is the dependent variable, as it is the outcome being measured.
• The group that got regular coffee: This is a level of the independent variable, not the independent variable itself.
• The group that got decaf: This is also a level of the independent variable, not the independent variable itself.
• Which beverage people got: This is the independent variable, as it is the factor being manipulated (regular coffee vs. decaf).

The independent variable is \\(\boxed{\text{which beverage people got}}\\).

The independent variable in Elsa's experiment is \\(\boxed{\text{which beverage people got}}\\).