Why do experiments have a control group as part of the design?

Question

to use as a backup, in case the experiment fails the first time

to help the scientists determine which variable is the dependent variable

to see if the treatment (changing the independent variable) has any effect

to minimize the number of variables in the experiment

Answer 1

Experiments have a control group primarily "to see if the treatment (changing the independent variable) has any effect."

The control group serves as a baseline or standard for comparison against the experimental group, which receives the treatment. By comparing the outcomes of the control group to those of the experimental group, scientists can determine whether any observed effects are due to the treatment itself or other factors. This design helps to isolate the effect of the independent variable on the dependent variable.