Question

over a 4-month period, among 100 people with a psychological disorder, patients who were given a high dose (877 mg/day) of a certain dietary supplement improved more than the placebo. the researchers kept track of and were aware of the dosages of supplements and placebos. complete parts a through h.
a) identify whether the above research is an observational study or an experiment.
the described research is an experiment

b) identify the subjects studied.
a. the subjects are psychological disorders.
b. the subjects are 100 people with a psychological disorder.
c. the subjects are the population of people with a psychological disorder.
d. the subjects are certain dietary supplements.

Explanation:

To determine the subjects studied, we analyze the research description. The study involves 100 people with a psychological disorder who were given different dosages (supplement or placebo) and their improvement was tracked. Option A is incorrect as psychological disorders are the condition, not the subjects. Option C refers to the population, but the study is on 100 specific people, not the entire population. Option D is incorrect as the dietary supplements are the treatment, not the subjects. So the subjects are the 100 people with a psychological disorder.

Answer:

B. The subjects are 100 people with a psychological disorder.