Final answer:
The control group in a study does not receive the experimental manipulation, whereas the experimental group does, allowing researchers to isolate the effects of the independent variable. Both groups are treated identically in all other aspects to ensure reliable results, often in a blind study to prevent experimenter bias.
Step-by-step explanation:
The difference between the control group and the experimental group in a scientific study is critical for understanding the effect of the variable that's being tested. In an ideal experimental setup, the two groups differ only in whether they are exposed to the experimental manipulation, which is the independent variable in the study. The control group doesn't receive the experimental manipulation but is treated in every other way like the experimental group, which includes being exposed to the independent variable. This ensures that any differences in the outcome, or dependent variable, can be attributed solely to the experimental manipulation and not to other factors.
To protect against experimenter bias, research studies are often designed to be blind, meaning that the subjects, and sometimes the researchers, do not know which group the subjects are in. This helps ensure that the results are not skewed by the researchers' expectations. In cases where the stakes are high, such as in clinical trials for new medications, having rigorous control and experimental groups is essential for concluding the efficacy of a treatment based on the gathered data.