This book brings together aspects of statistics and machine learning to provide a comprehensive guide to evaluating, interpreting and understanding biometric data. This professional book naturally leads to topics including data mining and prediction, which have been widely applied to other fields but not rigorously to biometrics, to be examined in detail. The book places an emphasis on the various performance measures available for biometric systems, what they mean, and when they should and should not be applied. The evaluation techniques are presented rigorously, however they are always accompanied by intuitive explanations that can be used to convey the essence of the statistical concepts to a general audience. This last point is an important one for the increased acceptance of biometrics among non-technical decision makers, and ultimately the general public.