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Chapter 2: Problem 48

Explain why some studies include both a control group and a placebo treatment. What additional comparisons are possible if both a control group and a placebo group are included?

Short Answer

Expert verified
Control groups and placebo treatments are used in studies to isolate the effects of the treatment being studied. In particular, control groups let researchers see the natural progression of a disease, while placebo groups control for the psychological effects of receiving treatment. Having both kinds of groups allows for more comparisons, such as measuring the real effect of a treatment beyond the placebo effect, and comparing the course of the disease or condition in each group.

Step by step solution

01

Understanding the Role of Control Groups and Placebo Treatments

A control group in a scientific study is a group that receives no treatment. They are used as a baseline to compare with the group that receives the actual treatment or intervention. On the other hand, a placebo treatment is a 'fake' treatment. Participants in a placebo group receive something that resembles the actual treatment, but has no therapeutic effect. It exists to control for the psychological effect of receiving treatment.
02

Reason for Including Both Control and Placebo Groups

The control and the placebo group play different roles in an experiment. The control group allows researchers to compare the natural progression of a disease or condition, whereas a placebo group controls for the psychological effect of receiving a treatment. This helps measure the 'placebo effect', which can be strong in many cases. Inclusion of both groups allows independent measurement of these two different effects.
03

Additional Comparisons Possible

If both a control group and a placebo group are used in an experiment, additional comparisons are possible. For example, researchers can determine whether the intervention has an effect over and above a placebo, that is, whether its effect is real and not simply a placebo. They can also compare how strong the placebo effect is compared to the effect of the intervention, or compare the rate of change or improvement in the condition between the control group, placebo group, and treatment group.

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Most popular questions from this chapter

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