statistics
posted by phia
A nutritionist wants to conduct a study to validate the efficacy of an herb as an aid in weight loss. She randomly assigns half of a group of overweight persons to a treatment group who are given the herb with instructions for its use and a planned diet for six weeks. The other half of the group is given parsley with the same instructions and same diet. A nurse at the nutrition center weighs each subject on Friday of each week. Select the potential source of confounding.
A. Placebo effect
B. Experimenter effect
C. Method of assignment to treatment and control groups
D. The study is essentially free of potential confounding.
My answer is B, but I think it could also be D
Respond to this Question
Similar Questions

math 9 ALGERBRA!!! HELP! please
elenear is three years older than herb. in twelve years the sum of their ages will be 51. how old is herb today? 
grade 9 math algerbra
elenear is three years older than herb. in twelve years the sum of their ages will be 51. how old is herb today? 
statistics
A group of adults of 200 aged 21 to 50 were selected from those entering Fit Right Health stores in Washington state, and were randomly divided into two groups. One group was given an herb and the othe placebo. After 6 months, the … 
Statistics
In a study of the effect of a medical treatment, a simple random sample of 300 of the 500 participating patients was assigned to the treatment group; the remaining patients formed the control group. When the patients were assessed … 
statistics
In a study of the effect of a medical treatment, a simple random sample of 300 of the 500 participating patients was assigned to the treatment group; the remaining patients formed the control group. When the patients were assessed … 
statistics
In a study of the effect of a medical treatment, a simple random sample of 300 of the 500 participating patients was assigned to the treatment group; the remaining patients formed the control group. When the patients were assessed … 
Statistics
A nutritionist wants to conduct a study to validate the efficacy of an herb as an aid in weight loss. She randomly assigns half of a group of overweight persons to a treatment group who are given the herb with instructions for its … 
Statistics
A nutritionist wants to conduct a study to validate the efficacy of an herb as an aid in weight loss. She randomly assigns half of a group of overweight persons to a treatment group who are given the herb with instructions for its … 
Stats
A nutritionist wants to conduct a study to validate the efficacy of an herb as an aid in weight loss. She randomly assigns half of a group of overweight persons to a treatment group who are given the herb with instructions for its … 
Stats  Help!!!
A nutritionist wants to conduct a study to validate the efficacy of an herb as an aid in weight loss. She randomly assigns half of a group of overweight persons to a treatment group who are given the herb with instructions for its …