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.     

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.

An initial examination of Singaporean seventh and eighth graders’ views of nature of science

Research in nature of science (NOS) among Asia-Pacific countries such as Singapore is arguably scarce. This study aimed to survey Singaporean secondary school students’ views of NOS with a newly developed instrument named Students’ Views of Nature of Science (SVNOS), which included various key aspects of NOS that are generally agreed upon by the science education community. Moreover, the relations between some demographic factors, including gender and grade, and students’ views of NOS were explored.

Sample, design and method

In total, 359 Singaporean seventh and eighth graders were invited to participate in this survey. The reliability, validity and structure of the SVNOS instrument were ensured by confirmatory factor analysis. A two-way multivariate analysis of variance was then conducted to determine the interaction effects between the gender variable and the grade-level variable.

Results and conclusion

The results indicated that the SVNOS instrument is reliable and valid to assess students’ views of NOS regarding seven distinct NOS dimensions. The male students were more prone to have constructivist-oriented views of NOS in the most of the SVNOS dimensions, while the female students conveyed more non-objective views of NOS. In addition, the eighth graders revealed more empiricist-oriented views of NOS than the seventh graders in several SVNOS dimensions. This result seems to contradict the results of previous studies that students’ views of NOS may reflect a developmental trend with their increasing educational experiences.     

Transactional Presence as a Critical Predictor of Success in Distance Learning

This paper argues that, apart from interactive activities, the perceptions of psychological presence that distance education students hold of their teachers, peer students, and the institution can be significant predictors of their learning. The "perception of presence" in this paper is defined as the degree to which a distance education student senses the availability of, and connectedness with, each party. This form of presence is designated here as "Transactional Presence" (TP). In this study, distance education student learning was assessed in the light of students' perceived learning achievement, satisfaction, and intent-to-persist. An analysis of student survey data indicates that a distance student's sense of institutional TP predicts all the selected measures to do with success in distance learning. While a sense of peer student TP is significantly related to satisfaction and intent-to-persist, the effect of teacher TP is found to relate only to student-perceived learning achievement. Implications of the TP construct are discussed with respect to the theory, research, and practice of distance education, along with recommendations for future research.     

Curriculum-based measurement in the content areas: vocabulary matching as an indicator of progress in social studies learning

The purpose of this study was to examine the reliability and validity of curriculum-based measures as indicator of growth in content-area learning. Participants were 58 students in 2 seventh-grade social studies classes. CBM measures were student- and administrator-read vocabulary-matching probes. Criterion measures were performance on a knowledge test, the social studies subtest of the Iowa Test of Basic Skills (ITBS), and student grades. Both the student- and examiner-read measures reflected change in performance; however, only the student-read measure resulted in interindividual differences in growth rates. Significant relations were found between the growth rates generated by the student-read vocabulary measure and student course grades, ITBS scores, and growth on the knowledge test. These results support the validity of a vocabulary-matching measure as an indicator of student learning in the content areas. The results are discussed in terms of the use of CBM as a system for monitoring performance and evaluating interventions for students with learning disabilities in content-area classrooms.     

Inquiry learning behaviors captured through screencasts in problem-based learning

This study examined the types of learning behaviors students demonstrated while performing inquiry tasks. It also explored the relationship between the learning behaviors and students’ domain knowledge. We observed fourteen students in five groups during a ninth-grade biology course. Three types of learning behaviors (inquiry, collaborative, and minimally productive behaviors) were identified and time on each type was measured. The results suggest that students demonstrated different patterns according to the types of learning behaviors. Correlation analysis revealed that learning outcomes had a strong positive correlation with the inquiry behaviors but a strong negative correlation with the minimally productive behaviors. The results suggest that attention should be paid to facilitate the more meaningful inquiry behaviors while reducing minimally productive behaviors.