6.2 Treatment and Control Groups
When performing an experiment, researchers should be careful to designate some subjects as part of a control group, and others as part of a treatment group. These separate groups are designed to help the researcher establish cause-and-effect through the experiment.
Typically, the control group will receive the “default”, or pre-existing, version of the concept, ideas, service, or product being tested. The treatment group, by contrast, will be exposed to the new concept, idea, service or product being tested.
Suppose a Professor wishes to try a new teaching style with a group of students. Instead of teaching the traditional way (through lectures, delivered in a “one-to-many” format) he will try a “flipped classroom” – in other words, students will come to class to actively present material to the rest of the group, rather than listen to the Professor’s delivery. They will also problem solve together and work on group assignments during the class periods.
Is this a good idea? Is it effective?
The way that a researcher could attempt to answer that question is by having some sections undergo the traditional approach, while other sections experience the “flipped classroom” approach. At the end of the semester, some assessment of learning outcomes could be performed, and the results of the two groups could be compared. For the sake of this example, we will assume that a large enough sample of students was used, and that the separation into the two groups was completely random.
In this scenario, the students who received the traditional education format would be the control group, whereas the ones who received the experimental style would be the treatment group.