The dependent variable is the measurable factor that changes due to the effect of another variable in an experiment or series of measurements. It has a relationship with the independent variable, which can be positive or negative. This means that the dependent variable changes in either the same direction or the opposite direction as the independent variable changes.
Scientists do not manipulate the dependent variable in an experiment. An example of a dependent variable is the test score of a student; the independent variable for an experiment investigating that might be the amount of time a student has to revise. Higher test scores that correlate with larger amounts of study time indicate a positive relationship between these dependent and independent variables. A high test score with a smaller amount of revision time indicates a negative relationship. Other names for the dependent variable include the response variable or outcome variable.
The independent variable is the factor in any study that receives manipulation. Examples of naturally independent variables include age and intelligence. Independent variables are also known as experimental and predictor variables. Control variables are extraneous factors that have the potential to affect the dependent variable. These are not a part of the hypothesis used as a basis for an experiment, but scientists must measure control variables to ensure they do not have a significant impact on the dependent variable.