Question

In an experiment, what is an independent variable?

1. the variable that will always prove a hypothesis correct


2. it is the group designed for comparison in the experiment


3. the variable that responds to what the scientist changes in an experiment


4. the variable a scientist purposely changes in an experiment

Answer 1

The independent variable (IV) is the characteristic of a psychology experiment that is manipulated or changed by researchers, not by other variables in the experiment.

For example, in an experiment about the effect of nutrients on crop growth: The independent variable is the amount of nutrients added to the crop field. The dependent variable is the biomass of the crops at harvest time.

Therefore : 3. the variable that responds to what the scientist changes in an experiment