In research, variables are any characteristics that can take on different values, such as height, age, temperature, or test scores. There are two types of variables: independent and dependent.

• Independent variable: An independent variable is the variable that is manipulated or varied in an experimental study to explore its effects. It is called "independent" because it is not influenced by any other variables in the study. Independent variables are also called explanatory variables, predictor variables, or treatment variables.

• Dependent variable: A dependent variable is the variable that depends on other factors. It is the variable that is being measured in the study or experiment. Dependent variables are also called response variables, outcome variables, or criterion variables.

To determine the independent and dependent variables in a study, you need to look for the following characteristics or keywords:

• Dependent variables:

  • Depend on other variables.
  • When you are 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:

  • Arent affected by any other variables that the study measures.
  • 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 manipulated by the researcher.

For example, if someone was studying the effects of pollution on asthma, the incidence of asthma would be the dependent variable, and pollution would be the independent variable.