Independent variable

Definition

Independent variable in plain English

The independent variable is the one thing YOU deliberately change in an experiment to see what it does — the cause you're testing. If you're checking whether studying longer raises test scores, the study time is the independent variable because you're the one setting it, and the score is what you measure in response. An easy memory trick: it's "independent" because it doesn't depend on the outcome — you decide it up front. Keeping everything else the same and changing just this one knob is what lets you claim it actually caused the result.

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