Parallel analysis (PA) is a useful empirical tool for assessing the number of factors in exploratory factor analysis. On conceptual and empirical grounds, we argue for a revision to PA that makes it more consistent with hypothesis testing. Using Monte Carlo methods, we evaluated the relative accuracy of the revised PA (R-PA) and traditional PA…

Traditional parallel analysis (T-PA) estimates the number of factors by sequentially comparing sample eigenvalues with eigenvalues for randomly generated data. Revised parallel analysis (R-PA) sequentially compares the "k"th eigenvalue for sample data to the "k"th eigenvalue for generated data sets, conditioned on"k"-…

We compared 5 different statistics (i.e., G index, gamma, "d'", sensitivity, specificity) used in the social sciences and medical diagnosis literatures to assess calibration accuracy in order to examine the relationship among them and to explore whether one statistic provided a best fitting general measure of accuracy. College…

The purpose of this study was to examine the internal structure, relationships with other variables, and diagnostic accuracy of scores on the Autism Diagnostic Observation Schedule-Generic (ADOS-G; Lord et al., 1999) for the purpose of diagnostic decision-making. Participants were 462 children enrolled in a public school district in the southern…

The development of executive functions in the preschool years is not fully understood. Although there exists a large body of research investigating the maturation of executive functioning in school-aged children, little is known about the emergence of such skills, in particular inhibition, among preschool-aged children. Understanding developmental…