Contents
- Index
- Previous
- Next
ProtoGenie Home Page
Why Use Groups?
Treatment Groups
If more than one treatment is being tested, groups are frequently used to sort out the effects of each treatment and combinations of treatments. In this situation, each treatment is assigned to a specific group. Consequently, they are referred to as "Treatment Groups."
Control Groups
Groups are used in experimental research to help distinguish between effects on subjects that are due to treatments and effects that are due to history and other threats to validity. Therefore, subjects in the typical control group are not presented any treatment.
Also, groups are used to determine whether a treatment has greater effects on one population than another. For example, a teaching method might be more effective with males than it is with females. In this case, there might be three groups: one consisting of male subjects, one consisting of female subjects, and one consisting of males and females who do not receive the treatment. These groups are generally called "Control Groups."
Random Assignment of Subjects to Groups at Run-time
See Random Assignment to Groups.