A researcher studied whether meeting regularly with a weight-loss counselor helps dieters lose weight. Eighty dieters were available for the study. Half the dieters, assigned at random, received weight-loss counseling. The other half did not. After six months, the weight lost by each dieter was measured. On the average, those who met regularly with a weight-loss counselor lost more weight than those who did not.
In order to create groups of subjects that should be similar, on average, in all respects, we use
A) lurking.
B) confounding.
C) randomization.
D) All of the above

Question

Quizplus · Accepted Answer

Randomization is the best method to create groups of subjects that are similar, on average, in all respects. This ensures that any differences in the outcome can be attributed to the treatment being studied and not to other factors. Lurking and confounding variables are potential sources of bias that can affect the results of a study, but randomization helps to control for these factors.

A Researcher Studied Whether Meeting Regularly with a Weight-Loss Counselor