what is the control in an experiment

In an experiment, the control is the group or condition that does not receive the experimental treatment and is used as a baseline to compare the results of the tested group.

What is the control in an experiment?

The control (often called the control group) is kept free from the change in the independent variable so you can see what would happen under “normal” conditions. It helps you tell whether any change in the experimental group is really caused by the treatment, or just by chance or other factors.

A classic example: in a drug study, the experimental group gets the new drug, while the control group gets no drug or a placebo. Afterward, researchers compare outcomes between the two groups to see if the drug made a real difference.

Key features of a control

• Not exposed to the independent variable or treatment.

• Serves as a baseline or standard for comparison.

• Kept as similar as possible to the experimental group in all other ways (age, conditions, etc.).

• Makes it easier to detect cause‑and‑effect relationships and avoid misleading results.

Why controls matter (quick story-style example)

Imagine you’re testing whether a new fertilizer makes plants grow taller.

• Experimental group: plants that get the new fertilizer.
• Control group: plants that get no fertilizer, but still receive the same water, light, and soil.

If the fertilized plants grow taller than the control plants, you can reasonably say the fertilizer likely caused the extra growth, because everything else was held the same.

Mini FAQ

How do you find the control in a description of an experiment?
Look for the group that did not receive the treatment or independent variable, but otherwise was handled the same as the experimental group.

Is “control” the same as “controlled variables”?
No. The control group is the no‑treatment baseline, while controlled variables are conditions you keep constant (like temperature or time) in all groups so they don’t affect the outcome.

Information gathered from public forums or data available on the internet and portrayed here.