Specification Search for Identifying the Correct Mean Trajectory in Polynomial Latent Growth Models

This study investigated the optimal strategy for model specification search under the latent growth modeling (LGM) framework, specifically on searching for the correct polynomial mean or average growth model when there is no a priori hypothesized model in the absence of theory. In this simulation study, the effectiveness of different starting models on the search of the true mean growth model was investigated in terms of the mean and within-subject variance-covariance (V-C) structure model. The results showed that specifying the most complex (i.e., unstructured) within-subject V-C structure with the use of LRT, ΔAIC, and ΔBIC achieved the highest recovery rate (>85%) of the true mean trajectory. Implications of the findings and limitations are discussed.     

Now I’m Ready: The Impact of a Professional Development Initiative on Faculty Concerns with Program Assessment

This article examines the impact of a faculty professional development effort on the understanding, confidence, and attitudes of education faculty related to program assessment activities. We applied literature on the adoption of innovations, institutional effectiveness, and professional development to a case study of a series of workshops on assessment. The results suggest that faculty members had improved skills and knowledge, understanding, confidence, and attitudes regarding assessment following the workshops. The opportunity for faculty members to collaborate with colleagues on assessment and to develop an understanding of the kinds of supports in place for assessment work were important elements in the gains.     

Career motivation of secondary students in STEM: a cross-cultural study between Korea and Indonesia

The purpose of this study was to understand the career motivation of secondary students in science, technology, engineering, and mathematics (STEM) by comparing Korean and Indonesian students. Effects of gender and educational level on students’ STEM career motivation were also examined. To test for differences, we used Rasch analysis, 3-way ANOVA, correlation analysis, and multiple group path analysis. STEM career motivation was found to be significantly affected by interactions between country, gender, and educational level. Overall, Indonesian students had more STEM career motivation than Korean students. Korean students showed larger gender differences in STEM career motivation than Indonesian students.     

Investigating the effect of school‐wide positive behavioral interventions and supports on student learning and behavioral problems in elementary and middle schools

Many states have scaled up School‐Wide Positive Behavioral Interventions and Supports (SW‐PBIS) with the goal of improving student behavior and academic outcomes. Although the effects of SW‐PBIS on behavioral and discipline outcomes have been promising, the findings for academic achievement have been inconclusive and are often limited to cross‐sectional data. This paper examined the longitudinal effect of SW‐PBIS on student behavioral problems and academic achievement growth in elementary and middle schools using propensity score matching. We found no statistically significant longitudinal effects of SW‐PBIS on either student behavior problems or academic achievement among elementary and middle schools in this quasi‐experimental design, even though the positive direction of longitudinal changes would be identified. The result raised questions about the efficacy of SW‐PBIS using a statewide achievement test when scaled up to a state level. Additional research is needed to better understand the impact of SW‐PBIS using rigorous scale‐up designs.     

Effects of Missing Data Methods in Structural Equation Modeling With Nonnormal Longitudinal Data

The purpose of this study is to investigate the effects of missing data techniques in longitudinal studies under diverse conditions. A Monte Carlo simulation examined the performance of 3 missing data methods in latent growth modeling: listwise deletion (LD), maximum likelihood estimation using the expectation and maximization algorithm with a nonnormality correction (robust ML), and the pairwise asymptotically distribution-free method (pairwise ADF). The effects of 3 independent variables (sample size, missing data mechanism, and distribution shape) were investigated on convergence rate, parameter and standard error estimation, and model fit. The results favored robust ML over LD and pairwise ADF in almost all respects. The exceptions included convergence rates under the most severe nonnormality in the missing not at random (MNAR) condition and recovery of standard error estimates across sample sizes. The results also indicate that nonnormality, small sample size, MNAR, and multicollinearity might adversely affect convergence rate and the validity of statistical inferences concerning parameter estimates and model fit statistics.     

The use of specially designed tasks to enhance student interest in the cadaver dissection laboratory

Cadaver dissection is a key component of anatomy education. Unfortunately, students sometimes regard the process of dissection as uninteresting or stressful. To make laboratory time more interesting and to encourage discussion and collaborative learning among medical students, specially designed tasks were assigned to students throughout dissection. Student response and the effects of the tasks on examination scores were analyzed. The subjects of this study were 154 medical students who attended the dissection laboratory in 2009. Four tasks were given to teams of seven to eight students over the course of 2 weeks of lower limb dissection. The tasks were designed such that the answers could not be obtained by referencing books or searching the Internet, but rather through careful observation of the cadavers and discussion among team members. Questionnaires were administered. The majority of students agreed that the tasks were interesting (68.0%), encouraged team discussion (76.8%), and facilitated their understanding of anatomy (72.8%). However, they did not prefer that additional tasks be assigned during the other laboratory sessions. When examination scores of those who responded positively were compared with those who responded neutrally or negatively, no statistically significant differences could be found. In conclusion, the specially designed tasks assigned to students in the cadaver dissection laboratory encouraged team discussion and collaborative learning, and thereby generated interest in laboratory work. However, knowledge acquisition was not improved.     

Migration distance-based platelet function analysis in a microfluidic system

Aggregation and adhesion of platelets to the vascular wall are shear-dependent processes that play critical roles in hemostasis and thrombosis at vascular injury sites. In this study, we designed a simple and rapid assay of platelet aggregation and adhesion in a microfluidic system. A shearing mechanism using a rotating stirrer provided adjustable shear rate and shearing time and induced platelet activation. When sheared blood was driven through the microchannel under vacuum pressure, shear-activated platelets adhered to a collagen-coated surface, causing blood flow to significantly slow and eventually stop. To measure platelet adhesion and aggregation, the migration distance (MD) of blood through the microchannel was monitored. As the microstirrer speed increased, MD initially decreased exponentially but then increased beyond a critical rpm. For platelet-excluded blood samples, there were no changes in MD with increasing stirrer speed. These findings imply that the stirrer provided sufficiently high shear to activate platelets and that blood MD is a potentially valuable index for measuring the shear-dependence of platelet activation. Our microfluidic system is quick and simple, while providing a precise assay to measure the effects of shear on platelet aggregation and adhesion.     

The effect of site quality on repurchase intention in Internet shopping through mediating variables: The case of university students in South Korea

We performed a study to determine the influence that site quality has on repurchase intention of Internet shopping through customer satisfaction, customer trust, and customer commitment. Appropriate measures were developed and tested on 230 university students of Gyeongnam province in South Korea with a cross-sectional questionnaire survey. The results of the empirical analysis confirmed that site quality can be conceptualized as a composite of six dimensions of shopping convenience, site design, information usefulness, transaction security, payment system, and customer communication. Second, site quality positively affected customer satisfaction and customer trust, but did not affect customer commitment and repurchase intention. Third, site quality can affect repurchase intention by enhancing or attenuating customer satisfaction, customer trust, and customer commitment in online transaction situation. The mediating effect of customer satisfaction, customer trust, and customer commitment between site quality and repurchase intention is identified. Fourth, site quality indirectly affected customer commitment through customer satisfaction. Customer satisfaction indirectly affected repurchase intention through customer trust and customer commitment. Thus, it is found that site quality can be a very important factor to enhance repurchase intention in the customer perspective.     

Classifying higher education institutions in Korea: a performance-based approach

The purpose of this study was to classify higher education institutions according to institutional performance rather than predetermined benchmarks. Institutional performance was defined as research performance and classified using Hierarchical Cluster Analysis, a statistical method that classifies objects according to specified classification factors. In the analysis, 47 Korean universities with doctoral programs were classified as research universities (seven universities), research active universities (14 universities), and doctoral universities (26 universities). In the detailed discussions, profiles of each group were analyzed and discussed; and, disciplinary classifications were conducted in engineering, natural science, and social science and humanities. In addition, to validate the classifications, the research performances of these categories were compared with those of U.S. peers. In the comparisons, the research performance of Korean universities was similar to that of U.S. peers. From the analysis, the classification results emerging from the performance-based approach were shown to be equivalent to that of conventional classifications using predetermined benchmarks.