Problem Sets and Solutions for Bayes Theorem, Base Rates, and Prediction

A persistent theme in these chapters is the important and underappreciated role base rates play in determining the diagnostic utility of a test. Meehl’s arguments are often technical and sometimes difficult to grasp on first reading. Fortunately, the math can be simplified by replacing some of his equations with formulas using more modern notation and by fleshing out other equations with fuller derivations. To help readers digest Meehl in a more palatable form, problems and worked solutions illustrate how base rates determine the ceiling of predictive accuracy. As an appetizer, let us begin by defining some key terms used in this chapter.