In scientific experiments, what is the term for the variable that is measured as the outcome?

In a scientific experiment, the dependent variable is the outcome that is measured. It is called “dependent” because its observed value may depend on changes in another variable, usually the independent variable.

For example, in a study of fertilizer and plant growth, the amount of fertilizer is the independent variable and the plant's height or mass is the dependent variable. In a medical experiment, dosage may be manipulated while symptom severity, blood pressure, or another measured response serves as the dependent variable.

The dependent variable is also called the response, outcome, output, target, or measured variable in different fields. It may be numerical, such as temperature or reaction time, or categorical, such as whether a patient improved. Researchers define how it will be measured before collecting data so that results can be compared consistently.

A common mix-up is treating “dependent” as meaning statistically independent or unreliable. The term describes its role in the study's design, not whether the measurements are mathematically independent. A control variable is held constant, while a confounding variable can distort the apparent relationship between the variables being studied.