Question

Why do scientists use control groups in experiments?

Answer 1

a reasearcher must only measure one variable at atime,and using a scientific control group gives reliable baseline data to compare their results with.

Answer 2

Scientists use control groups in experiments to have more reliable data and to minimize the errors in the experiments. Usually, scientists study about an effect of different factors one at a time so it is important to have control to avoid other factors that may affect the set-up.