Question

question
a study is planned to research the effects of drinking coffee on hours of sleep. would an experimental or observational study design be more appropriate?

select the correct answer below:
○ an observational study should be used because it is not possible to control whether or not a person drinks coffee.
○ an observational study should be used because it is not possible to control the number of hours of sleep a person has.
○ an experimental study should be used where the consumption of coffee is the experimental factor.
○ an experimental study should be used where the number of hours of sleep is the experimental factor.

Explanation:

Answer:

An experimental study should be used where the consumption of coffee is the experimental factor.