Chapter 6.1, Problem 6.3E

To determine

To explain why this fact makes any conclusion about cause and effect untrustworthy and use the language of lurking variables and confounding in the explanation and draw a picture to illustrate it.

Explanation of Solution

A lurking variable that has an important effect on the relationship among the variables in a study but is not one of the explanatory variables studied.

Two variables are confounded when their effects on a response variable cannot be distinguished from each other.

We are interested in the relationship between nursing and the mother’s attitude toward the child.

Women choose whether they nurse or bottle-feed. It is then possible that the choice affects the mother’s attitude toward the child because a mother who chooses to nurse might have a different attitude towards a child compared to mother who chooses to bottle-feed. The choice of the women is then a lurking variable that could confound the variable of the nursing or bottle feeding because we cannot differentiate between the choice and the effect of nursing/bottle-feeding o the mother.