Abstract
Many states now mandate early screening for dyslexia, but vary in how they address these mandates. There is confusion about the nature of screening versus diagnostic assessments, risk versus diagnosis, concurrent versus predictive validity, and inattention to indices of classification accuracy as the basis for determining risk. To help define what constitutes a screening assessment, we summarize efforts to develop short (3-5 min), teacher-administered screens that used multivariate strategies for variable selection, item response theory to select items that are most discriminating at a threshold for predicting risk, and statistical decision theory. These methods optimize prediction and lower the burden on teachers by reducing the number of items needed to evaluate risk. A specific goal of these efforts was to minimize decision errors that would result in the failure to identify a child as at risk of dyslexia/reading problems (false negatives) despite the inevitable increase in identifications of children who eventually perform in the typical range (false positives). Five screens, developed for different periods during kindergarten, Grade 1, and Grade 2, predicted outcomes measured later in the same school year (Grade 2) or in the subsequent year (Grade 1). The results of this approach to development are applicable to other screening methods, especially those that attempt to predict those children at risk of dyslexia prior to the onset of reading instruction. Without reliable and valid early predictive screening measures that reduce the burden on teachers, early intervention and prevention of dyslexia and related reading problems will be difficult.