Question

a dermatologist will conduct an experiment to investigate the effectiveness of a new drug to treat acne. the dermatologist has recruited 72 teenagers. each person in the experiment has acne and each person in the experiment will receive either the new drug or a placebo. after each person in the experiment uses either the new drug or the placebo for 2 weeks, the dermatologist will evaluate the improvement in acne severity for each person on a scale from 0 (no improvement) to 100 (complete cure). 11. what are the treatments in this experiment? 12. what are the experimental units? 13. what is the response variable? 14. what type of experimental design is this? 15. why is it important for the dermatologist to be blinded in this experiment?

Explanation:

1. Treatments are what is being administered to the experimental units. Here, it's the new drug and the placebo.
2. Experimental units are the entities on which the experiment is conducted, which are the 72 teenagers.
3. The response variable is what is being measured as an outcome, so it's the improvement in acne severity on a scale from 0 - 100.
4. This is a completely - randomized experimental design as subjects are randomly assigned to either the new drug or placebo group.
5. Blinding the dermatologist is important to prevent bias in the evaluation of acne severity improvement. If the dermatologist knows which subject received the drug or placebo, they may unconsciously rate the improvement differently.

Answer:

1. The treatments are the new drug and the placebo.
2. The experimental units are the 72 teenagers.
3. The response variable is the improvement in acne severity on a scale from 0 (no improvement) to 100 (complete cure).
4. The type of experimental design is a completely - randomized design.
5. It is important for the dermatologist to be blinded to prevent bias in the evaluation of acne severity improvement.