Consider an experiment designed to determine the effectiveness of a new drug. The drug is given to participants in the treatment group, while participants in the control group receive a placebo. For the set of result described, discuss whether there appears to be evidence that the treatment is effective.
82% of those in the treatment group showed improvement; 18% of those in the placebo group showed improvement.
In this experiment there are two groups. The first group is the treatment group. The treatment group receives the real treatment. Therefore, a higher percentage of those that show improvement in this group shows that the treatment is effective.
The second group is the placebo group. The placebo group lacks the active ingredients of the treatment being tested. This is to keep the placebo effect from affecting the results. The placebo effect refers to the situation in which patients improve simply because they believe they are receiving a useful treatment. Therefore, a lower parentage of those that show improvement in this group shows that the treatment is effective.
Therefore, since the treatment group had the higher percentage of improvements, there is good evidence that the treatment is effective.