Wendy added the same amount of water to two plants of the same variety. She placed them in the sun and added fertilizer to one plant but not to the other. She recorded the height of the plants after a week. What is the independent variable in the study?

The independent variable is that she added the same amount of water to both plants but gave fertilizer to one but not the other. The reason why is because the independent variable does not depend on another variable. In an experiment, the independent variable is the variable that is varied or manipulated by the researcher. The dependent variable is the response that is measured. In Wendy's experiment, the variable that is manipulated is the independent variable, which is how she goes about finding the outcome. The dependent variable is what she is trying to calculate or measure.