define dependent and independent variables in a study
An independent variable is a variable believed to affect the dependent variable. This is the variable that you, the researcher, will manipulate to see if it makes the dependent variable change. In our example of hungry people throwing a ball, our independent variable is how long it's been since they've eaten.
The independent (or manipulated) variable is something that the experimenter purposely changes or varies over the course of the investigation. The dependent (or responding) variable is the one that is observed and likely changes in response to the independent variable. For example, a student might change the position of a planeâs wing to see how it affects the average speed of a model plane. The wing position would be the independent variable- because the student purposely changes its location.