What is dependent and independent variable in research

Let's take the example of “Test Scores”. You want to see the effect of studying or sleeping on a test score. In the example, “test score” is the dependent variable. “Studying” or “sleeping” is the independent variable because these factors impact how much a student scores on the test.

In a well-designed experimental study, the independent variable is the only important difference between the experimental (e.g. treatment) and control (e.g. placebo) groups. The dependent variable is the variable being tested and measured in an experiment, and is 'dependent' on the independent variable.

In analytical health research there are generally two types of variables. Independent variables are what we expect will influence dependent variables. A Dependent variable is what happens as a result of the independent variable.

Dependent Variable The variable that depends on other factors that are measured. These variables are expected to change as a result of an experimental manipulation of the independent variable or variables.