Why might control groups be important in an experiment?

• A. They are used only in complex experiments
• B. Control groups provide a baseline for comparison
• C. Control groups are unnecessary if there are few variables
• D. All experiments must have control groups to be valid

Answer: (B)

Control groups play a crucial role in scientific experiments by providing a baseline for comparison against the experimental group, which undergoes the treatment or intervention being tested. This baseline helps determine whether any observed effects or changes in the experimental group can be attributed to the treatment, rather than other factors. By comparing results from the control group, which does not receive the treatment, with those from the experimental group, researchers can isolate the effects of the variable being tested and draw more accurate conclusions about its efficacy or impact.

Using control groups helps to enhance the reliability and validity of the experiment's findings, as it accounts for variables that could influence the outcome and provides a clearer understanding of the relationship between the treatment and the observed effects. This practice is fundamental in ensuring that scientific conclusions are well-founded and based on solid evidence.