In the experimental evaluation of a new drug, what is the purpose of a placebo?
a. A placebo increases the sample size.
b. A placebo prevents errors in recording of the data.
c. A placebo removes the bias of the physician in charge of the experiment.
d. A placebo removes the potential psychological bias of the patient in the study.
e. A placebo prevents sampling errors from compromising the results of the experiment.
Question 2
Suppose we want to examine the effect of a fertilizer on the size of zucchini produced, and therefore, we need to
establish the experimental and control groups. The control group for this experiment would be defined under which
conditions?
a. soil, fertilizer, water, sun, but no zucchini seeds
b. soil, fertilizer, water, sun, and zucchini seeds
c. soil, water, sun, and no zucchini seeds
d. soil, water, sun, and zucchini seeds
e. soil, water, and sun