Question

Researchers wanted to know if an herbal remedy could prevent or reduce the severity of the common cold. The researchers tested two levels of remedy, 5 mg per day and 10 mg per day versus a placebo. 200 participants were exposed to the cold virus; each participant was randomly assigned to the 5 mg, 10 mg, or placebo group. At the end of 7 days, each participant was rated by a medical expert on the severity of their cold from 0 (none) to 5 (very severe).

1.How many treatments are there?
2. What is the response variable?
3. Explain why this situation is an experiment and not an observational study.

Answer 1

The study has three treatments involving different doses of an herbal remedy and a placebo. The response variable is the severity of the common cold. The study is an experiment due to random assignment and controlled conditions.

Step-by-step explanation:

The study in question is designed to evaluate the efficacy of an herbal remedy in preventing or reducing the severity of the common cold. When analyzing the details of this study, we can identify several key components:

1. Treatments: There are three treatments being tested - a 5 mg dose of the herbal remedy, a 10 mg dose, and a placebo.
2. Response Variable: The primary response variable is the severity of the common cold, which is rated on a scale from 0 to 5.
3. As for why this is an experiment rather than an observational study, the key factor is the random assignment of participants to treatment groups and the controlled administration of the remedy, which allows researchers to establish a cause-and-effect relationship between the treatment and the outcome.

In summary, the study encompasses three treatments with the severity of cold symptoms being the response variable. The nature of this study as an experiment is affirmed by the structured intervention and random allocation, contrasting it with observational studies that do not involve such manipulation of variables.