Confounding factor (Confounding variable)

Extrinsic factor in a situation where a relationship between dependent and independent variables are involved, causing positive or negative misestimating. Mother’s education could be an example for such a factor when we try to estimate the relation between bottle-feeding (independent variable or cause) and colic suffering of babies (dependent variable or effect). Through an experiment it seems that baby colic occurs in infants that we bottle-fed most of the time, notwithstanding a mother’s knowledge how to use a bottle or breast-feed properly against extra air penetrating into baby’s digestion.