<p> Student retention, the practice of having a student repeat a grade level of schooling due to low academic performance or delayed behavioral and social development, is a common yet controversial educational practice in the United States. Extensive literature exists on the effects of retention on students&rsquo; academic outcomes, socialization, and self-esteem, but with mixed results. The perceptions of teachers and principals on the practice of retention have also been studied. Even though many school districts have policies stating that decisions on retaining students at the elementary level are made by teachers and parents/guardians, the perceptions of parents/guardians as compared to teachers on the practice of retention has not been thoroughly examined. This mixed methods study collected quantitative and qualitative data on the perceptions of teachers and parents/guardians on student retention through an established survey and through personal interviews. The study revealed that there are significant differences in the perceptions of parents/guardians as compared to teachers on when retention is appropriate for students. There are also differences in what teachers and parents/guardians identify as factors to consider for recommending retention and their long-term concerns for students when considering retention. Revealing these differences and understanding that both parties have an overall concern for the well-being of the student will help to bridge the communication gap between teachers and parents/guardians and guide them toward making collaborative decisions for students. Although this study is a first step toward this understanding and collaboration, there are many factors involved in making decisions on student retention, so these findings will require further research.</p><p>

<p> Mechanical gears can be as small as those in traditional mechanical watches or as large as those in mechanical marine turbines. They can be seen in almost all transportation tools, for example, bicycles, cars, trains and airplanes. Though they have been studied and refined for centuries, there are still some disadvantages. For instance, mechanical gears often create a large amount of noise and vibration. They require regular maintenance as the gears need to be lubricated. In addition, if a gear is overloaded it can catastrophically fail. </p><p> Unlike conventional mechanical gears, magnetic gears can create speed change without physical contact. The force between magnetic gears is not created by geared teeth but instead, it is created by the magnetic poles. There will be a small air gap between different rotors which means no lubricant or maintenance is required. When one rotor rotates, the other one will also rotate driven by magnetic forces. Since the permanent magnets are used, the forces will not recede or disappear as long as the magnets are not overheated. If overloaded, a magnetic gearbox will simply slip poles. Therefore, in many applications, magnetic gears can be more reliable, efficient and safer. </p><p> The goal of this research has been to investigate the torque capabilities of high gear ratio magnetic geared devices. The performance has been investigated based on the gear ratio and torque density. </p><p> A new type of flux focusing cycloidal magnetic gear (MG) was investigated that could operate at a gear ratio of -25:1. The flux focusing topology was used because it increased the air gap flux density and therefore enabled a higher torque density. Using 2-D finite element analysis (FEA), the volume torque density was calculated to be 291 Nm/L with an outer diameter of 0.228 m. A -20:1 prototype cycloidal magnetic gear was designed. It had a calculated volumetric torque density of 260 Nm/L. The cycloidal magnetic gear was mechanically difficult to construct and therefore only the inner rotor of the cycloidal magnetic gear was constructed. In addition, the eccentric air gap will cause bearing failure. </p><p> To achieve an even higher gear ratio, a nested multistage magnetic gear (MSMG) was designed with a 2-D FEA calculated torque density of 424 Nm/L. The desired gear ratio was 59:1 so that the performance could be compared with a Sumitomo mechanical gearbox which had the same gear ratio. In order to minimize the rotor torque ripple, the harmonic field interaction between the inner stage and the outer stage of the magnetic gear had to be mitigated. A unique flux concentration Halbach rotor structure was proposed. The rotor structure was shown to shield the outer rotor from the inner rotor harmonics. The nested multistage magnetic gear contains 4 rotors and complex mechanical structure. In order to provide sufficient mechanical support, the mechanical axial length had to be very large and this negated many of the benefits of using the nested coaxial rotor structure. </p><p> A two-stage series connected 59:1 gear ratio multistage magnetic gear was also designed for wind turbines. The 6.45:1 first stage magnetic gearbox had a diameter of 0.633 m and the 3-D FEA calculated peak torque and torque density were 4.79 kNm and 159 Nm/L. The measured torque and torque density were 4.25 kNm and 141 Nm/L. While the 9.14:1 second stage magnetic gearbox had a diameter of 0.507 m and the 3-D FEA calculated peak torque and torque density were 1.04 kNm and 136 Nm/L, respectively. The series connected multistage magnetic gear had the advantage of being more modular as different gear ratios can be obtained by changing the pole pair combinations for one of the series connected magnetic gears. </p><p> A two-stage series connected 59:1 gear ratio multistage magnetic gear was also designed for a hydropower application. Non-magnetic rods were used to reduce the losses and the mechanical deflection. The 2-D calculated torque density for the stage 1 magnetic gear was 371 Nm/L. And the 2-D calculated torque density was 344 Nm/L for the stage 2 magnetic gear. A stator was also designed that was inserted inside the stage 2 magnetic gear. In order to try to reduce the torque ripple, the stator had a fractional winding distribution with 1.25 slots/pole/phase. (Abstract shortened by ProQuest.) </p><p>

<p> This research explored the nuances of co-creating and implementing a co-constructed and reconceptualized Kindergarten mathematics curriculum including innovative teaching practices such as number talks, math baskets, and counting collections to examine their impact on a student's mathematical identity, mindset, and content knowledge. The goal of this research was to provide a counter-story on mathematics curriculum in an early elementary classroom setting with a focus on social justice and equity. The project employed qualitative methodologies using a bricolage approach. A critical theoretical framework and related postdiscourses guided my research design, data collection, and analysis. Data sources for this study included a reflective journal kept by myself as a teacher-researcher focused on mathematical curriculum experiences, semi-structured focus group discussions with students, and electronic student artifacts collected over a twelve-week period in the late fall and winter of a school year. Data was analyzed using open and thematic coding. The major themes that emerged were used to create a community autoethnographic narrative via a bricolage of vignettes. The large and overarching theme of social justice and equity permeated the research findings in connection with students establishing a mathematical identity and mathematical mindset. Other themes included: (a) "growing our math brains"; (b) culturally relevant pedagogy (CRP); (c) operating as a community of learners; (d) students taking ownership of their mathematical learning; (e) teacher as ethnographer, facilitator and co-creator of learning; (f) making math meaningful and tangible; (g) play, enjoyment, and fun during math learning; and (h) meeting or exceeding standards with a localized curriculum in lieu of following a standardized curriculum. The vignettes and subsequent analyses are not intended to be a replicable mathematics curriculum for Kindergarten students. Rather, the vignettes are intended to inspire teachers to reconceptualize mathematics curriculums that influence their young students' mathematical identities. It is suggested that a reconceptualized and co-constructed mathematics curriculum will have a lasting influence on the mathematical mindset and identities of young students.</p><p> Keywords: reconceptualized mathematics curriculum; mathematical identity; mathematical mindset; number talks; math baskets; criticalism; social justice and equity; bricolage; community autoethnography; Kindergarten; early childhood education</p><p>

<p> This study outlines essential frameworks of Reggio inspiration based on literature from the Educational Project of Reggio Emilia. The purpose of this study was to determine which Reggio inspired frameworks were valued and applied by teachers and instructional assistants (IAs) in the Early Childhood Center (ECC) at the Progressive Academy of Southeast Asia (PASA). The study also sought to provide feedback for educators in the ECC, now four years into the adoption of Reggio inspired values, as they work towards PASA&rsquo;s 2020 strategic goals of excellence, opportunities, and holistic care. Focus groups, observations, and interviews were conducted with ECC teachers and IAs as a part of a qualitative research design. Transcripts were coded for key words and phrases.&nbsp;Four themes emerged from the study: (1) there are six areas of alignment between participant perceptions of the Reggio inspired frameworks in the ECC at PASA, and their day-to-day practices of that work; (2) concept-based learning is one potential area for growth for the teacher and IA Reggio inspired practice in the ECC; (3) instructional assistants (IAs) experience limitations in their work environment that affect their capacity as Reggio inspired educators; and (4) inclusive education is a potential area for policy reform at PASA. This study highlights areas for further consideration and growth as the ECC works towards the 2020 goals of excellence, opportunities, and holistic care. The study also proposes frameworks that can be used by educators in other settings to examine their Reggio inspired practices. </p><p>

<p> The Effectiveness of Tiered Instruction in Elementary Schools Trident University International 2018 The purpose of this mixed research study was to explore the effectiveness of the tiered instruction and interventions for grades kindergarten through five at 2 elementary schools within a single charter school district in the Southern United States. The study is built on Swanson and Sachse-Lee&rsquo;s (2000) meta-analysis which identified the effects of Tier 3 interventions. The researcher requested secondary data consisting of pre-assessment and post-assessment results from the 2016 school year in the tiered instruction. A series of data points was used to determine if a student was successfully move from Tier III to Tier II due to the successful implementation of instruction. These data points were used to assess the effect of tiered interventions, including: NWEA MAP of Growth and the ACT Aspire for students in grades K-5. To gain a deeper understanding of teachers&rsquo; perspectives, a survey was distributed to 59 elementary certified teachers. A repeated measures ANOVA test was conducted for four dependent variables. When conducting this study, the researcher compared four groups in the multi-tiered instruction of the dependent variables and an expected medium effect (f = .25) based on the research. The Paired samples t-test and repeated measures ANOVA was conducted to test progress the participants in Tier 1, Tier 2, and Tier 3 made in their reading abilities. The power of .80% power (alpha = .05) was used to conduct the study. Of the 59 teachers, 55 teachers participated in the survey. The minimal sample size of the survey was 55 teachers. The questionnaire consisted of open-ended questions related to how teachers used the assessments to implement tiered instruction with fidelity, to have more targeted conversations during professional learning communities, become more strategic in the implementation of the targeted instruction, and effectively articulate to parents the skills the students need to improve on while providing simplistic ways to assist the students at home. The researcher used &ldquo;thematic analysis&rdquo; as a systematic process to formalize the identification and development of themes. The process consisted of coding text, developing descriptive themes, and generating analytical themes. The use of line-by-line coding enables the researcher to undertake what has been described as one of the key tasks in the synthesis of qualitative research: the <i>translation</i> of concepts from one study to another (Coffey &amp; Atkinson, 1996). This study provided district leaders, building administrators, and teaching staff empirical evidence to support the effectiveness of multi-tiered reading interventions at the elementary level. The multivariate analysis of the study showed: (1) Participation in Tier I instruction predicted student scores in Reading through the NWEA MAP of Growth and the ACT Aspire, (2) participation in Tier II instruction could not predict student scores in Reading through NWEA MAP of Growth, however; student scores could not be predicted in Reading through the ACT Aspire, and (3) participation in Tier III instruction could not predict student scores in Reading through NWEA MAP of Growth or ACT Aspire pre-assessment and post assessment. The findings support the effectiveness of multi-tiered instruction in elementary schools. When Tier I instruction is strong, Tier 2 and Tier 3 will be effective resulting in few students needing the extra support afforded in Tier 2 and Tier 3. Of the 172 students that moved from one tier to another, 28 students increased their learning and moved from Tier III to Tier II instruction. The researcher also discovered from the qualitative research conducted, regarding elementary needs, teachers desired to have smaller classrooms which would improve the effectiveness of implementing instruction. The smaller classroom size would not only increase learning for the struggling students, but also the students who have already mastered the essential skills being taught. The findings may give support for the educators who need empirical evidence to increase learning through multi-tiered instruction.</p><p>

<p>Preschool children hold immense writing potential that is rarely realized in traditional classrooms. This mixed-methods, quasi-experimental study focused on how best to teach these emergent writers. By comparing the effects of interactive writing, writing workshop, and traditional instruction, the study provided a clearer picture of how these instructional approaches influence students? writing achievement and processes. The quantitative results of the study pointed to the effectiveness of both writing workshop and interactive writing for improving students? foundational writing skills. The qualitative results supported these findings and highlighted how students differed in the extent they identified as authors and played in their writing. Based on these findings, both writing workshop and interactive writing might be effectively applied in preschool classrooms by empowering emergent writers and providing opportunities to write.

<p> <b>Purpose:</b> The purpose of this Delphi study was to identify the competencies that early care and education systems leaders should possess as perceived by a panel of early childhood systems leadership experts. This study also identified which leadership competencies experts perceive will have the most impact on transformation of the field into an organized system of practice.</p><p> <b>Methodology:</b> This study used a mixed-methods Delphi approach consisting of three electronic surveys to identify competencies needed by early care and education systems leaders as perceived by a panel of national experts. Round 1 consisted of open-ended questions. Round 2 asked the panelists to rate each competency&rsquo;s importance using a 6-point Likert scale. In Round 3 panelists were requested to choose which competencies were most important for systems leaders to impact the transformation of the field into an organized system of practice.</p><p> <b>Major Findings:</b> A quantitative analysis of Round 2 found that the expert panelists agreed on 65 competencies as important or very important for systems leaders to acquire. Some of the most highly rated competencies identified were <i>developing relationships and partnerships, valuing diversity, collaborative leadership skills</i>, and <i>commitment to equity</i>. In Round 3, 14 competencies were selected as necessary for systems leaders to impact transformation of the field, including <i> systems thinking, big picture perspective, commitment to equity</i>, and <i>knowledge of policy and legislation</i>. Through a qualitative literature analysis, the themes <i>systems thinking</i>, and <i> collaborative and inclusive leadership</i> were found to be most aligned with the research literature. A surprising finding was that the expert panelists did not rate <i>knowledge of child development</i> as important for systems leaders, which contrasted with the research literature. </p><p> <b>Recommendations for Future Research:</b> Include (a) replication of this study with representation from additional systems leaders throughout the country; (b) perceptions of stakeholders throughout the ECE workforce regarding leadership competencies, including diverse and marginalized populations and those in a variety of leadership roles; (c) tasks and objectives of systems leaders and a clear definition of their roles; and (d) impact of the absence or presence of knowledge of child development on the decisions of ECE systems leaders.</p><p>

The purpose of this study was to investigate the effects of variations in the day care environment on linguistic and social-emotional development of pre-school children in Singapore after home background has been taken into account. This study examined differences in the environment of 16 day care centres. Characteristics of the environment were assessed by the Early Childhood Environment Rating Scale, ECERS (Harms & Clifford, 1980) and the Target Child Method of Observation, TCM (Sylva, Roy & Painter, 1980). The ECERS measured the physical and programmatic features of day care centres and produced a total 'quality' score and seven subscale scores. These consisted of assessments of personal care and routines, furnishing and display, language-reasoning experiences, fine and gross motor activities, creative activities, social development and adult needs provided in day care centres. This rating scale was validated in Singapore and discriminant validity was established. Reliability was also obtained before proceeding with the assessment of the day care environments. The TCM investigated the interactive features of day care centres and consisted of typical activities and social interactions experienced by children. Inter-observer reliability was established and child behaviours were systematically observed and coded for 12,800 thirty-second intervals. Day care effects were investigated by assessing children at two time points. A pre-test,consisting of linguistic and social-emotional assessments, was conducted on 122 pre-school aged children at the beginning of the year and a post-test administered towards the end of the year. Data analysis was conducted by regressing these outcomes on the ECERS measure of the day care environment. T-test analyses were also conducted to investigate differences in typical child behaviours (as nasured by the TCM) between 'high' progress centres and 'low' progress centres. Child characteristics and home background variables were included in the analyses to control for possible confounding of the effects of the day care environment on children's outcomes. This study found that total centre 'quality' and specific subscales on the ECERS were related to some aspects of linguistic and social emotional development of children. Results also suggested that certain child activities and social interaction were associated with higher progress in language development.

abstract: This dissertation consists of three chapters. Chapter one examines whether spending different amount of time outdoors on weekends and weekdays change the estimates of the impact of ground level ozone on the incidents of respiratory disease and asthma in California. This chapter contributes to the literature that focuses on the short term effect of air pollution on public health. Using the American Time Use Survey data, I find that on average people spend 50 minutes outdoors on weekends more than weekdays. Incorporating this difference in estimating the health impact of ozone changes the results significantly, especially for adults 20-64. The specification also allows me to find a precise estimate for each day of the week. In chapter two I estimate the effect of exposure to ozone on skills of children aged 3 to 15 years. I use the Letter-Word (LW) test scores from the Panel Study of Income Dynamics (PSID) as a measure of children's skills. Due to omitted variable bias, OLS estimate of ozone effect on children's skill is positive and imprecisely estimated. To mitigate the omitted variable bias I use the instrumental variables approach. This method accounts for endogeneity of pollution. The effect of ozone on children's skills becomes negative but only marginally significant. In chapter three, I estimate a production function of skill formation for children 3 to 15 years old and simultaneously account for their childhood exposure to ozone. I find that a one standard deviation increase in ozone leads to a 0.07 standard deviation reduction in the LW test scores on average. The LW test score of 3 year olds drops by 0.10 standard deviation in response to one standard deviation increase in pollution levels, while for the 14 year olds this effect is only half as much, 0.04 standard deviation. I also find that households exhibit compensatory behavior and mitigate the negative effect of pollution by investing more on their children. I quantitatively demonstrate that certain policies, such as a reduction in pollution levels or income transfers to families, can remediate the negative impact of childhood exposure to pollution on adult outcomes. / Dissertation/Thesis / Doctoral Dissertation Economics 2017

A Thesis submitted in fulfilment of the degree Doctor of Education Faculty of Education and Social Sciences Mowbray Campus Cape Peninsula University of Technology, 2013 / The purpose of this study was to understand the development of preservice teachers’ knowledge for teaching early algebra as a result of an early algebra course and teaching practicum. Preservice teachers enter teacher education with a diversity of school experiences of learning algebra which usually involves a high degree of procedural understanding. This study argues the importance of preservice teachers having the experience and opportunity to develop both conceptual and procedural understanding of the mathematics they will teach. The research was based on a case study, using qualitative methodologies and framed within an interpretive paradigm. It included a group of third year preservice teachers studying for a Bachelor of Education degree in the General Education and Training (GET) band. The early algebra course, known as Maths 2, was designed to develop knowledge for teaching early algebra and to build mathematical proficiency through participation in a professional learning community. The design and content of the course were guided by Ball’s mathematical knowledge for teaching (MKfT) model and the choice of early algebra as functional thinking aligned with the goals of the Revised National Curriculum for Mathematics (RNCS) and the more recent Curriculum Assessment Policy Statement (CAPS) in the mathematics content area: patterns, functions and algebra. The preservice teachers’ development of knowledge for teaching early algebra was identified through their manifestations of knowledge for teaching early algebra. These manifestations were illustrated by preservice teachers’ verbal and written responses from lesson reflections, questionnaires as well as video recordings of selected lessons. Focus group interviews were used to investigate the role of the early algebra course (Maths 2) in developing preservice teachers’ knowledge for teaching early algebra. The findings indicate that preservice teachers developed both common content knowledge (CCK) and specialised content knowledge (SCK) for teaching early algebra. Their responses indicated a growing awareness of the development of their mathematical knowledge for teaching through their own experiences of a richer and connected algebra and through guided support and reflection in the process of learning and teaching.