Will taking antioxidants help prevent colon cancer?
A medical experiment divided subjects into four gruops:daily beta-carotene, daily vitamins C and E, all three vitamins every day or daily placebo to determine if they help prevent colon cancer.
1. What are the explanatory and response variables in this experiment?
My question: Is the placebo considered an explanatory variable??
I know the beta-carotene, vitaminds C and E, and all three vitamins are. The response variable is the incidence of cancer.
In this medical experiment, the explanatory variables are the different treatments given to the subjects, which are daily beta-carotene, daily vitamins C and E, all three vitamins every day, and daily placebo. The response variable is the incidence of colon cancer, which is being observed and measured to determine if the different treatments have any effect in preventing it.
As for your question, the placebo is not considered an explanatory variable in this experiment. An explanatory variable is one that is intentionally manipulated or controlled by the researchers to determine its effect on the response variable. In this case, the researchers are interested in testing the effect of different vitamins and antioxidants on the incidence of colon cancer, and the placebo serves as a control group for comparison. The placebo is not actively manipulated or controlled like the other treatments; instead, it is inert (usually a sugar pill or an identical-looking but medically inactive substance) and given to the subjects to account for any potential placebo effects. Its purpose is to provide a baseline against which the effects of the active treatments can be evaluated.