Factor structure and specific variance of the WPPSI subtests at six age levels

The Wechsler Preschool and Primary Scale of Intelligence (WPPSI) was factor analyzed at each of six age levels between 4 and 6½ years through the method of principal factors. A two-factor solution, corresponding essentially to Wechsler's a priori grouping of the subtests into a Verbal and nonverbal or Performance scale, best described the 11 WPPSI subtests at each age level. Examination of the common, specific, and error variance components of the subtests across age levels indicated adequate test specificity to allow for individual interpretation of all subtests except Information and Comprehension when the null hypothesis model of ipsative interpretation of individual tests is employed.     

Preparing Doctoral-Level Consultants for Systems Change: Implementing and Supervising Multitiered Practices in Early Childhood Education

Implementing changes that support a preventative approach in early childhood education (ECE) requires the collaboration of skilled professionals. The present case study describes a change effort to implement multitiered systems of support (MTSS) in early childhood settings that included collaboration of agency personnel, school psychology program faculty and trainees, and ECE faculty. It describes a competency-based training initiative that provides applied experiences in consultation, supervision, and change facilitation for systems change efforts. The implementation of a systems-level approach for promoting positive behavior at three ECE agencies is described, with resulting teacher and child outcomes. Implications for future consultation research, training, and practice are discussed in relation to a consultation training model that provides competency-based field experiences to support change in ECE.     

Football boundary-layer separation via dust experiments

A method of examining the separation of the boundary layer of air from a sports ball, specifically a football, is presented. Using a ball launcher, a non-spinning football is fired into a dust cloud. A high-speed camera records the ball passing through the dust cloud. Unlike wind-tunnel methods, the dust method described here allows for the examination of the boundary-layer separation without a ball-supporting arrangement. Boundary-layer separation for speeds surrounding the drag crisis is studied. Though the general trend is for the boundary layer to separate farther back on the ball as the ball’s centre-of-mass speed increases, anomalous behaviour is seen just past the drag crisis, namely a rise in the separation angle, followed by an expected decrease.