Seeing the Forest and the Trees: Comparison of Two IRTree Models to Investigate the Impact of Full Versus Endpoint-Only Response Option Labeling

In this study, we examined the results and interpretations produced from two different IRTree models—one using paths consisting of only dichotomous decisions, and one using paths consisting of both dichotomous and polytomous decisions. We used data from two versions of an impulsivity measure. In the first version, all the response options had labels; in the second version, only the endpoints were labeled. Based on past research, we hypothesized that the endpoints would be selected more frequently in the endpoint-only labeled condition, and the midpoint response option would be selected more frequently in the fully labeled condition. Results from the two models (dichotomous and polytomous) were similar and indicated that our hypotheses were partially supported—specifically, there was no consistent pattern in terms of which condition saw a higher frequency of midpoint response selection. However, our hypotheses regarding extreme responding in the endpoint-only labeling condition were supported.     

Development of Automated Scoring Algorithms for Complex Performance Assessments: A Comparison of Two Approaches

Performance assessments are typically scored by having experts rate individual performances. The cost associated with using expert raters may represent a serious limitation in many large-scale testing programs. The use of raters may also introduce an additional source of error into the assessment. These limitations have motivated development of automated scoring systems for performance assessments. Preliminary research has shown these systems to have application across a variety of tasks ranging from simple mathematics to architectural problem solving. This study extends research on automated scoring by comparing alternative automated systems for scoring a computer simulation test of physicians'patient management skills; one system uses regression-derived weights for components of the performance, the other uses complex rules to map performances into score levels. The procedures are evaluated by comparing the resulting scores to expert ratings of the same performances.     

Estimation of MIMIC Model Parameters with Multilevel Data

The purpose of this simulation study was to assess the performance of latent variable models that take into account the complex sampling mechanism that often underlies data used in educational, psychological, and other social science research. Analyses were conducted using the multiple indicator multiple cause (MIMIC) model, which is a flexible and effective tool for relating observed and latent variables. The data were simulated in a hierarchical framework (e.g., individuals nested in schools) so that a multilevel modeling approach would be appropriate. Analyses were conducted accounting for and not accounting for the nested data to determine the impact of ignoring such multilevel data structures in full structural equation models. Results highlight the differences in modeling results when the analytic strategy is congruent with the data structure and what occurs when this congruency is absent. Type I error rates and power for the standard and multilevel methods were similar for within-cluster variables and for the multilevel model with between-cluster variables. However, Type I error rates were inflated for the standard approach when modeling between-cluster variables.     

A social perspective on teaching and learning in the context of computer-mediated communication in teacher education

Abstract

In a context where ever greater emphasis is placed on the need to exploit the potential of information and communications technology, this article argues the need for a theoretical underpinning to such developments. In higher education, the emphasis is often placed on the assumed improved cost-effectiveness associated with ‘flexible’ and ‘independent’ student learning as one of the major benefits, although such notions as flexible and independent learning tend to be taken for granted. It is argued further that even where benefits to learning are emphasised, these are often founded on relatively impoverished views of learning. Often such views fit with a technocentric and positivist perspective on learning, emphasising as they do individualism, information delivery and a limited role for the tutor. This article outlines an alternative theoretical perspective based upon Vygotskian social psychology, activity theory and social practice. Such a perspective is characterised by an emphasis on interaction, communication and collaboration. Learning itself is seen as an aspect of participation in communities of practice, in which the human relationships between teachers and students are seen as fundamental. The theory is exemplified with reference to the use of computer-mediated communication in teacher education using FirstClass computer conferencing software.     

Interaction of wrestling shoe and competition surface: effects on coefficient of friction with implications for injury

The purpose of this study was to determine whether there is a significant difference in the co-efficient of friction (Fc) between old versus new wrestling shoes and mats and to investigate the effect of perspiration. Fc was measured by dragging a weighted shoe over a wrestling mat surface and measuring the vertical and horizontal forces produced. Three different shoe conditions were assessed over two mat types for both wet and dry conditions for a total of 12 conditions. To simulate the wet condition, saline solution was smeared over the surface of the mat. There was a significant effect of shoe, mat, and wet/dry conditions. In addition, significant interactions of shoe by mat, shoe by dry/wet, and mat by dry/wet were observed. Overall, Fc was 36% higher for the new wrestling mat compared to the old wrestling mat. Application of the saline solution reduced Fc by 14% compared to the dry condition. Comparison of the mean Fc for all three shoe types revealed the Fc for the older design shoe was 23% to 28% lower than the brand new shoe and the worn newer design, respectively. A high Fc, such as in the new mat/new shoe combination, has the potential to increase the risk of knee and ankle injuries by fixing the foot more securely to the ground.