Personal predictions are often optimistically biased. This simple observation has troubling implications for psychologists, economists, and decision theorists concerned with rationality and the accuracy of self-knowledge (Armor & Taylor, 2002; Krizan & Windschitl, 2007; Sweeny, Carroll, & Shepperd, 2006). However, normative conclusions about the impropriety of optimistic bias rest on an unteste...

BACKGROUND Optimal cutoff values for tests results involving continuous variables are often derived in a data-driven way. This approach, however, may lead to overly optimistic measures of diagnostic accuracy. We evaluated the magnitude of the bias in sensitivity and specificity associated with data-driven selection of cutoff values and examined potential solutions to reduce this bias. METHODS...