A pharmaceutical company is testing a new drug that may improve thyroid health. They gather 150 volunteers who will be split into two groups. One group is given the drug, and the other group is given a placebo. The administrators of the experiment alphabetized the names of the volunteers and then flipped a coin. Based on the coin flip, they assigned the first 75 names to the drug group and assigned the remaining 75 names to the placebo group. The volunteers are not told which group they are in.

Question

After several months of the volunteers taking either the drug or the placebo twice weekly, the administrators determine that 59 of the 75 volunteers in the drug group showed substantially improved thyroid health, and 34 of the 75 volunteers in the placebo group showed substantially improved thyroid health.

Is it appropriate for the experiment administrators to conclude that the drug improves thyroid health? Explain.

No. Randomization was not properly applied when determining group assignments, thus invalidating the conclusion.

Yes. The difference in results is large enough that the method of group assignments does not matter in deciding whether the conclusion is valid or not.

No. The placebo group fared better than the drug group.

Yes. Randomization was applied when determining group assignments, thus validating the conclusion.

Answer 1

No. It is not appropriate for the experiment administrators to conclude that the drug improves thyroid health. The method of group assignment was not truly random, as it was based on the alphabetized names of the volunteers and a coin flip. This could introduce bias into the results, as certain characteristics could be more prevalent in one group compared to the other. In order to draw valid conclusions, a truly random method of group assignment should be used to ensure that the groups are comparable at baseline.