A Systematic Analysis of Experimental Studies Targeting Fractions for Students with Mathematics Difficulties

Developing an understanding of fractions is critical and is an educational focus, as reflected in national standards and principles. This study conducted a quantitative synthesis of 22 experimental studies to investigate the overall efficacy of previously conducted fraction interventions compared to standard instruction. Instruction type and achievement level were used to examine variations of the effect sizes. The results indicated that intervention was more effective than standard instruction only in problem‐solving domains, and the effects were differentiated by instruction type and achievement level. This study provides a diagnostic view of the current state of U.S. mathematics education on fractions, along with insights for future directions in fraction instruction, particularly focusing on students with mathematics difficulties. Educational implications and limitations are discussed.     

Density-dependent separation of encapsulated cells in a microfluidic channel by using a standing surface acoustic wave

This study presents a method for density-based separation of monodisperse encapsulated cells using a standing surface acoustic wave (SSAW) in a microchannel. Even though monodisperse polymer beads can be generated by the state-of-the-art technology in microfluidics, the quantity of encapsulated cells cannot be controlled precisely. In the present study, mono-disperse alginate beads in a laminar flow can be separated based on their density using acoustophoresis. A mixture of beads of equal sizes but dissimilar densities was hydrodynamically focused at the entrance and then actively driven toward the sidewalls by a SSAW. The lateral displacement of a bead is proportional to the density of the bead, i.e., the number of encapsulated cells in an alginate bead. Under optimized conditions, the recovery rate of a target bead group (large-cell-quantity alginate beads) reached up to 97% at a rate of 2300 beads per minute. A cell viability test also confirmed that the encapsulated cells were hardly damaged by the acoustic force. Moreover, cell-encapsulating beads that were cultured for 1 day were separated in a similar manner. In conclusion, this study demonstrated that a SSAW can successfully separate monodisperse particles by their density. With the present technique for separating cell-encapsulating beads, the current cell engineering technology can be significantly advanced.     

The Contribution of HBCUS to the Preparation of African American Women for Stem Careers: A Case Study

This study uses case study analysis to explore the ways that Spelman College, a historically Black women’s college, promotes the attainment of African American women in STEM fields. Although limited to one institution, the findings shed light on the ways that institutional characteristics, policies, and practices may mitigate the barriers that limit attainment of African American women in STEM fields. Drawing on the findings, the paper concludes with recommendations for improving policy and practice as well as recommendations for additional fruitful research.     

When tensions between ideology and practice become personal: Unpacking mentorship in early childhood teacher education

University-based teacher education programs are criticized for being too theoretical, disconnected from the everyday realities of schools. To bridge this gap, teacher education programs give students year-long field experiences under the joint tutelage of mentor teachers and university faculty. However, this assumes that mentor teachers will not only be exemplary teachers, but skilled mentors as well. This article explores the tensions between the theoretical and practical work of teaching within mentoring relationships, specifically in spaces where teacher agency is limited by political, social, and cultural factors. The sociocultural, language approaches in many teacher education programs are seen as idealistic when pushed up against skills-based language approaches, advocated in classrooms. Using qualitative methods, this project follows three mentor/mentee pairs as they negotiate their relationships in an urban area in the Southwest United States. While all three pre-service teachers strongly believed that learning was a social practice, constructed through child inquiry and play, they struggled to maintain their ideologies and beliefs during their field experience. Pre-service teachers held firmly to their beliefs about teaching and learning, but holding onto these beliefs were wrought with personal and philosophical tensions. Pre-service teachers found limited agency in their practice and little support in implementing their own practices. Most importantly, unequal power dynamics and communication issues were obstacles towards mutually beneficial mentorship. Thus, preservice programs must address the importance of developing and cultivating the mentor/mentee relationship—a relationship that is pivotal in the construction of preservice teachers’ identities and practices.     

The effect of self‐directed work teams on work ethic

This study examined the work ethic of manufacturing machine operators between self‐directed work teams and traditional work groups using four work ethic subscales: dependable, considerate, ambitious, and cooperative (Dawson, 1999 ; Petty, 1991 ). Differences in measured work ethic scores were also compared across six demographic variables: age, gender, level of education, years of full‐time work experience, years of experience as a supervisor, and work shift preference. Findings showed that there were significant differences in the work ethic between those two team structures and age groups. Implications for future research were presented.     

Infusing Culturally Responsive Science Curriculum into Early Childhood Teacher Preparation

Research in Science Education - Previous research studies in early childhood teacher education have indicated that teacher candidates are not adequately prepared to demonstrate the knowledge and...     

Comparisons of Three Empirical Methods for Partial Factorial Invariance: Forward,Backward, and Factor-Ratio Tests

When factorial invariance is violated, a possible first step in locating the source of violation(s) might be to pursue partial factorial invariance (PFI). Two commonly used methods for PFI are sequential use of the modification index (backward MI method) and the factor-ratio test. In this study, we propose a simple forward method using the confidence interval (forward CI method). We compare the performances of the aforementioned 3 methods under various simulated PFI conditions. Results indicate that the forward CI method using 99% CIs has the highest perfect recovery rates and the lowest Type I error rates. A performance that is competitive with this is that produced by the backward method with the more conservative criterion (MI = 6.635). Consistently delivering the poorest performance, regardless of the chosen confidence level, was the factor-ratio test. Also discussed are the work’s contribution, implications, and limitations.     

韩国消费者对中国冰箱选择的研究

本研究以首尔(Seoul)的MBA学生为对象,实证分析了中国的国家形象、中国冰箱的功能属性和品牌个性对于韩国消费者的中国冰箱选择具有什么影响。结果表明,韩国消费者考虑购买中国冰箱时,除了国家形象、功能属性以外还受到品牌个性因素的影响。本研究指出了进入韩国的中国企业应开发与国家形象有关的、有个性的品牌产品,即品牌个性会提高品牌知名度,增加企业信赖度,从而成为韩国市场上更受欢迎的品牌,也将为有效的品牌市场导向提供产品差别化,这样可以使中国企业在竞争中获得优势。