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31.
The purpose of this ITEMS module is to provide an introduction to differential item functioning (DIF) analysis using mixture item response models. The mixture item response models for DIF analysis involve comparing item profiles across latent groups, instead of manifest groups. First, an overview of DIF analysis based on latent groups, called latent DIF analysis, is provided and its applications in the literature are surveyed. Then, the methodological issues pertaining to latent DIF analysis are described, including mixture item response models, parameter estimation, and latent DIF detection methods. Finally, recommended steps for latent DIF analysis are illustrated using empirical data. 相似文献
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This article addresses the issue of how to detect item preknowledge using item response time data in two computer‐based large‐scale licensure examinations. Item preknowledge is indicated by an unexpected short response time and a correct response. Two samples were used for detecting item preknowledge for each examination. The first sample was from the early stage of the operational test and was used for item calibration. The second sample was from the late stage of the operational test, which may feature item preknowledge. The purpose of this research was to explore whether there was evidence of item preknowledge and compromised items in the second sample using the parameters estimated from the first sample. The results showed that for one nonadaptive operational examination, two items (of 111) were potentially exposed, and two candidates (of 1,172) showed some indications of preknowledge on multiple items. For another licensure examination that featured computerized adaptive testing, there was no indication of item preknowledge or compromised items. Implications for detected aberrant examinees and compromised items are discussed in the article. 相似文献
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David James Woo 《Globalisation, Societies & Education》2015,13(4):455-470
An international school may make organisational choices that divide the school by curriculum, grade-level, language and location. This article explores how a school’s organisational stratification impacts how the school supports changing teaching and learning practices through technology. The article draws from case data of technology integration specialists at international schools in Hong Kong. A variety of organisational sections and responses to imbalances in technological pedagogical support between sections are presented. The findings highlight how stratification may not only act as an appropriate valve for change and facilitate intercultural exchange through technology but also perpetuate existing inequalities within and between schools. 相似文献
35.
Focusing suspended particles in a fluid into a single file is often necessary prior to continuous-flow detection, analysis, and separation. Electrokinetic particle focusing has been demonstrated in constricted microchannels by the use of the constriction-induced dielectrophoresis. However, previous studies on this subject have been limited to Newtonian fluids only. We report in this paper an experimental investigation of the viscoelastic effects on electrokinetic particle focusing in non-Newtonian polyethylene oxide solutions through a constricted microchannel. The width of the focused particle stream is found NOT to decrease with the increase in DC electric field, which is different from that in Newtonian fluids. Moreover, particle aggregations are observed at relatively high electric fields to first form inside the constriction. They can then either move forward and exit the constriction in an explosive mode or roll back to the constriction entrance for further accumulations. These unexpected phenomena are distinct from the findings in our earlier paper [Lu et al., Biomicrofluidics 8, 021802 (2014)], where particles are observed to oscillate inside the constriction and not to pass through until a chain of sufficient length is formed. They are speculated to be a consequence of the fluid viscoelasticity effects. 相似文献
36.
Infants and toddlers leverage their understanding of action goals to evaluate agents who help others
Why do infants and toddlers prefer helpers? Four experiments (conducted from 2019–2022; n = 136, 66% White, 15% Asian, 4% Black, 2% Hispanic/Latino, 13% multiracial, majority USA) investigated whether infants and toddlers favor agents whose actions allow others to achieve their goals. In the key experiment, 8-month-old infants and 15-month-old toddlers viewed a protagonist who tried and failed to open a box that contained a toy while two other agents (helpers) observed; then the toys were exchanged and the helpers opened different boxes. Infants and toddlers differently evaluated the two helpers, consistent with their developing means-end understanding. Together, the present four experiments connect infants' and toddlers' evaluations of helping to their understanding of goal-directed behavior. 相似文献
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John DuBose Xinyu Lu Saurin Patel Shizhi Qian Sang Woo Joo Xiangchun Xuan 《Biomicrofluidics》2014,8(1)
Shape is an intrinsic marker of cell cycle, an important factor for identifying a bioparticle, and also a useful indicator of cell state for disease diagnostics. Therefore, shape can be a specific marker in label-free particle and cell separation for various chemical and biological applications. We demonstrate in this work a continuous-flow electrical sorting of spherical and peanut-shaped particles of similar volumes in an asymmetric double-spiral microchannel. It exploits curvature-induced dielectrophoresis to focus particles to a tight stream in the first spiral without any sheath flow and subsequently displace them to shape-dependent flow paths in the second spiral without any external force. We also develop a numerical model to simulate and understand this shape-based particle sorting in spiral microchannels. The predicted particle trajectories agree qualitatively with the experimental observation. 相似文献
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Kihyun Kim Silvana Trimi Hyesung Park Shanggeun Rhee 《Decision Sciences Journal of Innovative Education》2012,10(4):575-587
Course Management Systems (CMSs) in higher education have emerged as one of the most widely adopted e‐learning platforms. This study examines the success of e‐learning CMSs based on user satisfaction and benefits. Using DeLone and McLean's information system success model as a theoretical framework, we analyze the success of e‐learning CMSs in five dimensions: system quality, information quality, instructional quality, user satisfaction, and CMS benefits. An analysis of survey data collected from students participating in a university‐wide CMS shows that system quality, information quality, and instructional quality positively influence user satisfaction, which, in turn, increases the benefits of CMSs. By providing a comprehensive framework for the critical success factors in e‐learning CMSs and their causal relationships, this study provides practical implications for managing e‐learning courses and resources for a more flexible and effective CMS‐centered, e‐learning environment. 相似文献
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Korean politicians, particularly National Assembly members, have embraced the internet as a major means of communication for managing election campaigns and maintaining relationships with (potential) supporters during non-election periods. An increasing number of National Assembly members have become aware of the considerable influence that the internet has on their constituents, and thus, this study determines whether there are significant differences in online networks of National Assembly members and examines the relationship among National Assembly members and that between those members and their constituents to determine whether Twitter is used as a tool for communication as well as deliberation. The data were drawn from homepages, blogs, and Twitter pages of the members of the 18th National Assembly in April 2010. The results indicate that National Assembly members tended to have a more equal relationship in the Twitter network than in the homepage or blog network. More importantly, the members were linked mainly to fellow politicians in the same party, and thus, they used Twitter to communicate more with fellow politicians than with their constituents. 相似文献
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As youth in contemporary societies grow increasingly dependent on digital media, media education has become a policy consideration, particularly in wired parts of the non-Western world. Due to rapid adoption rates, media penetration, and positive attitudes toward new and innovative technologies, Korea presents an ideal test case for understanding the everyday impact of digital media. The purpose of this paper is to examine the national policies and public discourse concerning digital media education in a rapidly growing market. Specifically, this study considers the development of a standardized educational program for youth in Korea. To frame this analysis, we present an overview of the types of digital media education and trends at the national policy level among English-speaking countries. This is supported by a review of literature focusing on the use of digital media among youth, supplemented by current digital media usage statistics among Korean youth and an overview of Korean government policy programs. A case study of Web site analysis is presented to illustrate implications and stimulate discussion regarding educational policy. 相似文献