A variable is anything that the study measures. Read through your source, looking for the following characteristics or keywords to identify the dependent and independent variables in your study.
Dependent variables:
• Dependent variables depend on other variables. For example, if someone were studying the effects of pollution on asthma, the incidence of asthma would be the dependent variable.
• When searching for relationships between variables, you are trying to find what makes the dependent variable change.
• The dependent variable is sometimes called the “response,” the “symptoms”, or the “outcome”.
• The dependent variable is often the focus of the research study.
Independent variables:
• Independent variables aren’t affected by any other variables that the study measures. The researcher often manipulates independent variables in a study. For example, if someone were studying the effect of different dosages to treat symptoms, the independent variable would be the dose.
• When you are searching for relationships between variables, you are trying to see if the independent variable causes some kind of change in the dependent variable.
• The independent variable can be a “treatment” (such as a drug dosage), a “risk factor” (such as diet), an intervention, or a predictor (such as weight or age).
• The independent variable could be a natural difference (such as gender), or it could be varied by the researcher intentionally.
An independent variable can affect a dependent variable, but a dependent variable can't affect an independent variable.