Chapter 4.2, Problem 55E

To determine

To explain why it was necessary to include a control group in this experiment.

Explanation of Solution

In this study, the researchers wants to study that if the extracts of the avocado and soybean oils can be used to help relieve the pain for subjects with joint stiffness due to arthritis.

Thus, the researchers include two groups for study i.e. one group whom the avocado and soybean unsaponifiables (ASU) medicines were given and the others whom the placebo were given for the experiment. The control group is defined as the group in an experiment or study that does not receive treatment by the researchers and is then used as a benchmark to measure how the other tested subjects do. Thus, we can conclude that the control group is important to see whether the new medicine ASUs are effective in giving result or not and helping the patients in their pain or not while comparing it to the other group chosen i.e. control group.