Question

A group of researchers is designing an experiment to test whether an herbal supplement will help people lose weight. The researchers selected a sample of 500 adults who want to lose weight, and over the next four months, 250 of them will take the herbal supplement daily whereas the remaining 250 will take a placebo daily. At the end of the four months, the researchers will compare the weight loss for the two groups.

Why is it important that the researchers use randomization to assign each of the adults who want to lose weight to a treatment group? Select all true statements.

A)Randomization eliminates lurking variables from the experiment.

B)Randomization prevents the researchers from specifically assigning all adults who exercise regularly to take the herbal supplement daily.

C)Randomization ensures each treatment group will be similar in everything except the type of pill taken.

D)Randomization ensures that there will be an equal number of adults who want to lose weight in each treatment group.

E)Randomization prevents the adults who want to lose weight from selecting their own treatment group.

Answer 1

Randomization is important to eliminate lurking variables, ensure similar treatment groups, and prevent self-selection bias.

Step-by-step explanation:

Randomization is important in assigning each adult to a treatment group because:

1. Randomization eliminates lurking variables from the experiment. By randomly assigning adults to either the herbal supplement or placebo group, any potential confounding variables that could impact weight loss will be evenly distributed between the groups.
2. Randomization ensures each treatment group will be similar. This means that both groups will be comparable in all aspects except for the type of pill taken. This allows the researchers to confidently attribute any differences in weight loss to the herbal supplement.
3. Randomization prevents the adults from selecting their own treatment group. If the adults were allowed to choose their own treatment group, there could be self-selection bias, as certain individuals may have preconceived notions about the effectiveness of the herbal supplement.