Question

Determine whether the follow descriptions correspond to an observational study (OS), a controlled experiment (CE), or a double blind experiment (DBE). Write the abbreviations above as your answers. (without the parenthesis)

(a)  A group of 500 adult males entered a study in which half would be fed a high fiber diet while the other half would be fed a minimal fiber diet in order to determine the effect of fiber on cholesterol.
answer:

(b)  A doctor gives half of his/her patients in a study a treatment and the other half a placebo, but the patients do not know which they received.
answer:

(c)  A nurse gives a group of patients either the drug being studied or a placebo; however neither the nurse nor the patient knows which they are receiving. Only the person who prepared the doses knows.
answer:

Answer 1

Ans: (a) The correct ans is CE (Controlled experiment.)

since the males are being assigned to two groups - one with high fiber content and the other with minimal fiber diet

(b) The correct ans is CE (Controlled Experimnent)

• In a controlled experiment, we assign people or things to groups and apply some treatment to one of the groups, while the other group does not receive the treatment .

(c) The correct ans is DBE ( Double blind experiment)

A double-blind study is a study in which both the person implementing the experiment and the participant(s) are not aware of which individual is receiving the experimental treatment. The purpose of a double-blind experiment is to ensure that the results are not biased