Question

Medical wonders is a specialized interior design company focused on healing artwork. the ceo, kathleen kelledy claims that artwork has healing effects for patients staying in a hospital, as

Answer 1

, as measured by reduced length of stay. I believe in this case her response is completely randomized design.
In completely randomized design, the subject would be assigned treatments, vaccine and placebon in a completely random order, which make it become easiest in the term of analysis and convenience.