A new cream was developed to reduce the irritation caused by poison ivy. To test the effectiveness, researchers put 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 assigned to the group with the new cream, and 50 were assigned to the group with the cream with no active ingredient. After three days, technicians recorded the subjects’ level of irritation. Which of the following would benefit this experiment the most?
This experiment should be single blind. The subjects will not know which treatment they are receiving to control for the placebo effect, but the technicians need to know which group received the new cream.
This experiment should be double blind. Neither the subject nor the technician knows which group is receiving the new cream to control for the placebo effect, and the response measured is not affected.
This experiment should be single blind. The subjects know which treatment they are receiving but the technicians do not know which group received the new cream, so the response being measured is not affected.
This experiment should not use blinding. It is unethical for the subjects not to know which treatment they are receiving, placebo or new cream, and for the technicians not to know which group received which treatment.
The subjects don't know which cream they have but the technicians do.
If the subject knows which cream they have then they can be influenced by the placebo effect. If they don't know but the technicians do then the technicians will be able to look at unbiased responses from the subjects and tell if it works or not. If the technicians don't know which cream each subject has then they won't be able to learn anything from the responses. The technicians need to know which cream each subject has and the subjects can't know which cream they had.
The probability is 3/14. There are 2 multiples of 4 in 14, which is 8 and 12. There is only 1 multiple of 6 in 14 which is 12. 1+2=3. It is possible outcomes over total outcomes so 3/14.
