what are independent and dependent variables in science

Independent variables are what you change, and dependent variables are what you measure in response. In simple terms: the independent variable is the cause , and the dependent variable is the effect.

Simple example

If you test how sunlight affects plant growth:

• Independent variable: amount of sunlight.

• Dependent variable: how much the plant grows.

Easy way to remember

• Independent = you choose or control it.

• Dependent = it depends on what you changed.

Another example

If you study whether more study time improves test scores:

• Independent variable: study time.

• Dependent variable: test score.

Quick tip

A good science question often looks like: “How does X affect Y?” In that setup, X is usually the independent variable, and Y is usually the dependent variable.