What is the purpose of a positive control group in an experiment?

A positive control group is critical in scientific experiments as it serves to confirm that the experimental setup is functioning as intended. This means that, when a positive control is included, the researchers can compare the results from this group to those obtained from the experimental group. If the positive control group produces expected, well-understood results, it validates that the experiment's conditions are suitable for detecting the effects of the experimental variable.

In essence, having a positive control helps identify any potential issues with the experiment that might prevent the detection of a response, thereby ensuring the reliability and accuracy of the results obtained from the experimental treatment. This aspect of experimental design is vital to drawing valid conclusions from a study.