Control groups are an important part of scientific research. They are used to compare the results of a study to a group that has not been exposed to the same conditions. Juntas are a type of control group in which the participants are all members of the same group, such as a family or a community. Normals are another type of control group in which the participants are randomly selected from the general population. Both types of control groups are used to ensure that the results of a study are accurate and unbiased.