Launching the Virtual Academic Center: Issues and Challenges in Innovation

In October 2010, the University of Southern California School of Social Work entered the online education environment with the launch of the first national web-based MSW program. After an initial enrollment of 80 students, in just 3 years this state-of-the-art MSW, offered in a technology-advanced synchronous and asynchronous format, has generated an enrollment of 2,000 students residing in 38 states. The development and rapid growth of the Virtual Academic Center has not been without significant challenges, the most substantial of which has been the creation of a national field education program. This paper describes the MSW courses taught in the online environment, and pedagogical hurdles faced in order to maintain the educational quality that is the hallmark of the School's campus-based MSW program.     

Describing the plastic deformation of aluminium softball bats

Hollow aluminium bats were introduced over 30 years ago to provide improved durability over wooden bats. Since their introduction, however, interest in hollow bats has focused almost exclusively around their hitting performance. The aim of this study was to take advantage of the progress that has been made in predicting bat performance using finite elements and apply it to describe bat durability. Accordingly, the plastic deformation from a ball impact of a single-wall aluminum bat was numerically modelled. The bat deformation from the finite-element analysis was then compared with experiment using a high-speed bat test machine. The ball was modelled as an isotropic, homogeneous, viscoelastic sphere. The viscoelastic parameters of the ball model were found from instrumented, high-speed, rigid-wall ball impacts. The rigid-wall ball impacts were modelled numerically and showed good agreement with the experimentally obtained response. The strain response of the combined bat-ball model was verified with a strain-gauged bat at intermediate ball impact speeds in the elastic range. The strain response of the bat-ball model exhibited positive correlation with the experimental measurements. High-speed bat-ball impacts were performed experimentally and simulated numerically at increasing impact speeds which induced correspondingly increased dent sizes in the bat. The plastic deformation from the numerical model found good agreement with experiment provided the aluminium work hardening and strain rate effects were appropriately described. The inclusion of strain rate effects was shown to have a significant effect on the bat deformations produced in the finite-element simulations. They also helped explain the existence of high bat stresses found in many performance models.     

Measurement of teacher performance: A study in instrument development

The procedures used to produce a research-based teaching evaluation system, containing low-inference indicators of effective and ineffective teacher behavior, included instrument development, content validation, and field testing. An extensive reliability study produced estimates for three types of consistency: intercoder agreement (r = 0.85), stability across teaching situations r = 0.86, and discriminant reliability among teachers (r = 0.79). The norming component of the study conducted in 45 schools, generated over 1200 observations of current teacher practice at all grade levels and in various subject areas. The results indicated the substantially generic nature of these behaviors; only grade level and instructional method (interactive, lecture, and independent seatwork) produced meaningful differences among groups of teachers. In addition, the average teacher used most of the effective behaviors (70%), and a few of the ineffective behaviors (8%) during observation. These results support the instrument's value in teacher training, remediation, and evaluation.     

Establishing reliability of biomechanical data using univariate and multivariate approaches

The purpose of this study was to use generalizability theory with both univariate and multivariate approaches to examine reliability of total body center of mass (CM) values calculated from cinematographical data. Twenty-eight college-aged male volunteers were filmed by a LOCAM camera at 100 fps while performing the basic locomotion skill of walking. Film analysis was conducted on each subject using six frames of film depicting a one-stride walking cycle consisting of right heel strike, right foot flat, left toe-off, left heel strike, left foot flat, and right toe-off. Nineteen segmental endpoints and a reference point were digitized by three experienced plotters. The digitizing sequence was replicated three times by each plotter. A FORTRAN program calculated nine CM values (three plotters by three repetitions) for each subject filmed in each of the six positions of the stride. The x- and y-coordinates of the CM values were the dependent variables analyzed by fully crossed 3-way univariate and multivariate ANOVAs (subjects by plotters by repetitions). All measurement facets were considered to be random. Results indicate that there was very little repetition error but considerable interplotter error for most frames. Phi-coefficients for x- and y-coordinates, separately, fluctuated across frames. The univariate values for the x-coordinates were similar but slightly less than the multivariate values. The Phi-coefficients for Y, however, were considerably lower than the multivariate values. The multivariate Phi-coefficients for generalizing over three plotters and three repetitions ranged from .82 to .90.(ABSTRACT TRUNCATED AT 250 WORDS)