Which of the following statements is true about the benefits of random assignment?
A new cream was developed to reduce the irritation
caused by poison ivy. To test the effectiveness,
researchers placed an ad online asking for volunteers
to participate in the study. One hundred subjects
replied and were informed that one group would
receive the new cream and the other would receive a
cream with no active ingredient. All 100 subjects were
exposed to poison ivy. Fifty were then randomly
assigned to the group with the new cream, and 50
were randomly assigned to the group with the cream
with no active ingredient. After three days, the
subjects' level of irritation was measured.
O The variability between each subject may not be
evenly distributed between the two groups, so any
observed differences in the level of irritation
between the two groups would not be due to the
new cream
O The variability between each subject would be
evenly distributed between the two groups, so any
observed differences in the level of irritation
between the two groups are more likely due to the
new cream
O The variability between each type of cream would
be evenly distributed between the two groups, so
any observed differences in the level of irritation
between the two groups are guaranteed to be due
to the subjects.
O The variability between each