Unconstrained Structural Equation Models of Latent Interactions: Contrasting Residual- and Mean-Centered Approaches

Little, Bovaird and Widaman (2006) proposed an unconstrained approach with residual centering for estimating latent interaction effects as an alternative to the mean-centered approach proposed by Marsh, Wen, and Hau (2004, 2006). Little et al. also differed from Marsh et al. in the number of indicators used to infer the latent interaction factor and how they were represented, but this issue is separate from the mean versus residual centering distinction that was their primary focus. However, their implementation of the Marsh et al. mean-centered approach failed to incorporate the mean structure that Marsh et al. argued was necessary to obtain unbiased estimates. One might suppose that their new approach would suffer this same problem, an issue not addressed by Little et al. However, we demonstrate here why the Little et al. approach obviates this requirement that heretofore was thought to be necessary for all constrained, partially constrained, and unconstrained approaches. Both the Marsh et al. and Little et al. unconstrained approaches typically result in similar results and are much easier to implement than traditional constrained approaches. They differ primarily in that the Little et al. approach is a 2-step approach involving a potentially large number of separate analyses prior to estimating the structural equation model that apparently does not require the estimation of a mean structure, whereas the Marsh et al. approach is a 1-step approach that includes a mean structure.     

Indirect Impact: How Early Childhood Educator Training and Coaching Impacted the Acquisition of Literacy Skills in Preschool Students

Learning to read becomes a difficult task for many children, particularly if they have not been reared in early childhood settings where literacy-based activities, interactions, or materials are prevalent. This study examined the impact that providing a college-level course in research-based instructional strategies for literacy development to early childhood educators had on the development of early reading skills in the preschool children they taught. In addition, impact on children’s rates of literacy skill attainment was examined when a coaching component (i.e., a Literacy Coach) was added.     

The Influence of Teachers’ Efficacy and Beliefs Regarding Mathematics Instruction in the Early Childhood Classroom

This was a correlational study conducted with a population of prekindergarten educators from a large, metropolitan school district. The purpose was to examine if there were relationships between and among early childhood teachers’ sense of self-efficacy, their beliefs about the importance of mathematics, and their mathematics instructional practices. Examining teachers’ efficacy and beliefs can inform educational practice and help to differentiate between more and less successful instructional practices when teaching mathematics in the early childhood classroom. Data were collected on teacher efficacy and teacher beliefs about the importance of mathematics with two self-report questionnaires. The hypothesis that the teachers higher in efficacy will rate the importance of mathematics higher on the teacher-belief scale than the teachers with lower efficacy was found to be true with this sample, but the correlation was weak. The level of efficacy of the early childhood teachers in this sample confirmed that in assessing their capabilities, they rate themselves high in instructional strategies, classroom management, and student engagement. The early childhood teachers did not rate their belief in mathematics as high as their efficacy. Observations of mathematics instructional practices were conducted with twenty teachers. It was hypothesized that the combination of high teacher efficacy and high teacher mathematics beliefs would show alignment with the presence of standards-based mathematics instructional practices. The results were not statistically significant. No correlation signals a need for more research to explore what other personal or external factors relate to mathematics instructional practices in the early childhood classroom. The research may inform pre kindergarten teachers and teacher educators about effective instructional strategies and knowledge needed to launch early childhood students on a developmentally appropriate pathway to mathematical literacy.     

Preservice Teachers’ Images of Scientists: Do Prior Science Experiences Make a Difference?

This article presents the results of a mixed methods study that used the Draw-a-Scientist Test as a visual tool for exploring preservice teachers’ beliefs about scientists. A questionnaire was also administered to 165 students who were enrolled in elementary (K–8) and secondary (8–12) science methods courses. Taken as a whole, the images drawn by preservice teachers reflected the stereotype of a scientist as a man with a wild hairdo who wears a lab coat and glasses while working in a laboratory setting. However, results indicated statistically significant differences in stereotypical components of representations of scientists depending on preservice teachers’ program and previous science experiences. Post degree students in secondary science methods courses created images of scientists with fewer stereotypical elements than drawings created by students in the regular elementary program.     

The Process of Fostering Consultee Development During Instructional Consultation

This investigation examines how the process of instructional consultation (IC) supports consultees' problem-solving and fosters change in how the consultees understand pertinent work problems. The setting was a mid-Atlantic elementary school's Instructional Consultation Team, and the participants were 13 case manager consultants and 5 teacher consultees. A micro-ethnographic research approach was used and 4 primary sources of data collected: interviews, direct observations, consultation documents, and IC training documents. Analysis of the data uncovered 4 general themes related to the participants' problem-solving and evolving understanding of the work issues. In the discussion, the question of how IC is a constructive process that promotes consultees' development is considered.     

Student-centredness: the link between transforming students and transforming ourselves

It is widely accepted in the higher education literature that a student-centred approach is pedagogically superior to a teacher-centred approach. In this paper, we explore the notion of student-centredness as a threshold concept and the implications this might have for academic staff development. We argue that the term student-centred in the Rogerian sense implies a focus on the person of the student and is deeply resonant with Barnett's assertion that the emergent being of the student is as important as the development of skills and knowledge. To facilitate transformative learning in higher education an academic must know how to value the person of the student in the learning process. Academic staff development initiatives need to work with the person of the academic and take into account the level of personal development required for each academic to be able to facilitate this kind of learning.     

Validation of a videogrammetry technique for analysing American football helmet kinematics

ABSTRACT

Professional American football games are recorded in digital video with multiple cameras, often at high resolution and high frame rates. The purpose of this study was to evaluate the accuracy of a videogrammetry technique to calculate translational and rotational helmet velocity before, during and after a helmet impact. In total, 10 football impacts were staged in a National Football League (NFL) stadium by propelling helmeted 50th percentile male crash test dummies into each other or the ground at speeds and orientations representative of concussive impacts for NFL players. The tests were recorded by experienced sports film crews to obtain video coverage and quality typically available for NFL games. A videogrammetry procedure was used to track the position and rotation of the helmet throughout the relevant time interval of the head impact. Compared with rigidly mounted retroreflective marker three dimensional (3-D) motion tracking that was concurrently collected in the experiments, videogrammetry accurately calculated changes in translational and rotational velocity of the helmet using high frame rate (two cameras at 240 Hz) video (7% and 15% error, respectively). Low frame rate (2 cameras at 60 Hz) video was adequate for calculating pre-impact translational velocity but not for calculating the translational or rotational velocity change of the helmet during impact.