A control group in an experiment is a group of participants that does not receive the experimental treatment or intervention being tested. Instead, this group is kept under standard or normal conditions to serve as a baseline for comparison with the experimental group, which does receive the treatment
. The main purpose of the control group is to isolate the effect of the independent variable (the treatment) by providing a reference point. By comparing outcomes between the control group and the experimental group, researchers can determine whether any observed changes are truly due to the treatment or caused by other factors
. Typically, the control group may receive no treatment, a placebo (an inert substance with no therapeutic effect), or a standard treatment whose effects are already known. This setup helps minimize bias and confounding variables, ensuring that differences in results can be attributed to the treatment alone
. Control groups are essential for establishing causality and improving the reliability and validity of experimental results across fields such as medicine, psychology, biology, and social sciences
. In summary:
- Control group: Does not receive the experimental treatment; serves as a baseline.
- Experimental group: Receives the treatment or intervention being tested.
- Purpose: To isolate the effect of the treatment by comparison.
- May receive: No treatment, placebo, or standard treatment.
- Importance: Minimizes confounding variables and bias, enabling valid conclusions about the treatment's effect
This fundamental design element allows researchers to draw accurate conclusions about whether the treatment causes the observed effects.
