Spurious Latent Classes in the Mixture Rasch Model

Mixture Rasch models have been used to study a number of psychometric issues such as goodness of fit, response strategy differences, strategy shifts, and multidimensionality. Although these models offer the potential for improving understanding of the latent variables being measured, under some conditions overextraction of latent classes may occur, potentially leading to misinterpretation of results. In this study, a mixture Rasch model was applied to data from a statewide test that was initially calibrated to conform to a 3‐parameter logistic (3PL) model. Results suggested how latent classes could be explained and also suggested that these latent classes might be due to applying a mixture Rasch model to 3PL data. To support this latter conjecture, a simulation study was presented to demonstrate how data generated to fit a one‐class 2‐parameter logistic (2PL) model required more than one class when fit with a mixture Rasch model.     

Mother–child joint writing in Chinese kindergarteners: metalinguistic awareness,maternal mediation and literacy acquisition

The present study examined the relations of Chinese word reading and writing to both maternal mediation of writing and a number of metalinguistic and cognitive skills in 63 Hong Kong Chinese kindergarteners. The whole process of maternal mediation of writing, in which mothers individually facilitated their children's writing of 12 two‐character words in their own ways, was videotaped. This study replicated and extended previous work on the cognitive strategies mothers use to help children in writing Chinese words. Mothers' typical mediation strategies were positively and significantly associated with both children's independent word reading and writing. In addition, maternal mediation of writing was uniquely associated with Chinese word reading, but not word writing, even with metalinguistic and cognitive skills, including phonological awareness, morphological awareness, orthographic processing and visual knowledge, statistically controlled. Findings underscore the importance of mothers' early scaffolding in facilitating children's literacy acquisition.     

A meta-analysis of outcome studies of visual-based instruction

This article describes a statistical integration of findings from 74 studies of visualbased college teaching. In the typical study, students learned slightly more from visual-based instruction than from conventional teaching. In the typical study, visual-based instruction had no special effect on course completion, student attitudes, or the correlation between aptitude and achievement. Students were equally likely to complete visual-based and conventional classes; their attitudes toward the two kinds of classes were very similar; and aptitude played a strong role in determining student achievement in each kind of class. This study was supported by National Science Foundation Grant SED 77-18566.     

Assessment for Effective Intervention: Enrichment Science Academic Program

Israel suffers from a growing problem of socio-economic gaps between those who live in the center of the country and residents of outlying areas. As a result, there is a low level of accessibility to higher education among the peripheral population. The goal of the Sidney Warren Science Education Center for Youth at Tel-Hai College is to strengthen the potential of middle and high school students and encourage them to pursue higher education, with an emphasis on majoring in science and technology. This study investigated the implementation and evaluation of the enrichment science academic program, as an example of informal learning environment, with an emphasis on physics studies. About 500 students conducted feedback survey after participating in science activities in four domains: biology, chemistry, physics, and computer science. Results indicated high level of satisfaction among the students. No differences were found with respect to gender excluding in physics with a positive attitudes advantage among boys. In order to get a deeper understanding of this finding, about 70 additional students conducted special questionnaires, both 1 week before the physics enrichment day and at the end of that day. Questionnaires were intended to assess both their attitudes toward physics and their knowledge and conceptions of the physical concept “pressure.” We found that the activity moderately improved boys’ attitudes toward physics, but that girls displayed decreased interest in and lower self-efficacy toward physics. Research results were used to the improvement of the instructional design of the physics activity demonstrating internal evaluation process for effective intervention.