A confounding variable is one that influences the dependent or outcome variable but was not separated from the independent variable. As seen from the statistical study shown in the step by step section below, there are confounding variables which may affect the outcome together with the dosage used by the designer of the experiment. As biological processes are usually complicated, the are other factors (such as race, gender, age, health conditions, daily diet, hobbies) which may affect the outcomes. A carefully designed experiment will use control groups to eliminate all possible confounding factors.
Work Step by Step
According to a pilot study of 20 people conducted at the University of Minnesota, daily doses of a compound called arabinogalactan over a period of 6 months resulted in a significant increase in the beneficial lactobacillus species of bacteria.