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Developing a Three-Dimensional View of Science Teaching: A Tool to Support Preservice Teacher Discourse
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| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Journal of Science Teacher Education |
| Volume / Edisi | : | 30 (No. 1-2) |
| Halaman | : | 101–121 |
| Abstrak | : | The Next Generation Science Standards (NGSS) and the Framework for K-12 Science Education (NRC, 2012) on which they are based, describe a new vision for science education that includes having students learn science in a way that more closely aligns to how scientists and engineers work and think. Accomplishing this goal will require teacher educators to make important shifts in the ways they prepare future science teachers (NRC, 2012). Many science teaching methods courses are being reformed to better support future science teachers to meet the ambitious goals of the NGSS. Specifically, these reform efforts require evidence-based and stan dards-aligned tools to help preservice teachers align instruction with the new science standards. This study utilized the methodology of Improvement Science “Plan, Do Study, Act” cycles in order to design a Three-Dimensional Mapping Tool (3D Map) as a visual scaffold for use in science teaching methods courses to support preservice teachers in unpacking the components of NGSS and to promote discourse related to the three-dimensionality of planning instruction. The 3D Map provides a visualization of key elements of the NGSS, while being flexible enough to accommodate established teaching strategies. |
Model Selection for High-Dimensional Quadratic Regression via Regularization
| Pengarang | : | Ning Hao |
| Nama Majalah/Jurnal | : | Journal of the American Statistical Association |
| Volume / Edisi | : | 113 (No. 522) |
| Halaman | : | 615-625 |
| Abstrak | : | Quadratic regression (QR) models naturally extend linear models by considering interaction effects between the covariates. To conduct model selection in QR, it is important to maintain the hierarchical model structure between main effects and interaction effects. Existing regularization methods generally achieve this goal by solving complex optimization problems, which usually demands high computational cost and hence are not feasible for high-dimensional data. This article focuses on scalable regularization methods for model selection in high-dimensional QR. We first consider two-stage regularization methods and establish theoretical properties of the two-stage LASSO. Then, a new regularization method, called regularization algorithm under marginality principle (RAMP), is proposed to compute a hierarchy-preserving regularization solution path efficiently. Both methods are further extended to solve generalized QR models. Numerical results are also shown to demonstrate performance of the methods. Supplementary materials for this article are available online. |
A Qualitative Case Study of Field-Based Teacher Education: One Candidate’s Evolving Expertise of Science Teaching for Emergent Bilinguals
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Journal of Science Teacher Education |
| Volume / Edisi | : | 30 (No. 1-2) |
| Halaman | : | 80–100 |
| Abstrak | : | Teacher education programs are responsible for preparing science teachers for today’s culturally and linguistically diverse classrooms, which includes preparing them to support students’ science learning and language development. Given the rapid growth in linguistic diversity across the country, science teacher preparation for English learners, referred to here as emergent bilinguals, is particularly critical. Although research-based pedagogical practices have been established for both science learning and language development, the fields remain separated in preparatory programs, which makes it unlikely that tea chers will merge the 2 in future practice. To date, research has begun to explore professional development efforts with in-service teachers focused on science education for emergent bilinguals, but studies involving preservice science teachers are scant. Working within a socio cultural paradigm, this single-case study uses narrative methods to explore the following question: How does field-based teacher educa tion promote and influence the development of professional expertise for teaching emergent bilinguals in secondary science classrooms? Analyzing data collected over 2 years, we present findings from a secondary science teacher candidate’s experiences across a field based teacher education program that prioritizes understandings, knowledge, and skills for emergent bilinguals. We discuss implications for science teacher educators seeking to design effective field-based programs that prioritize emergent bilinguals. |
Science Education Trajectories: Charting the Course for Teachers, Educators, Researchers, and Policymakers
| Pengarang | : | Luft, Julie A. ,Whitworth, Brooke A.,Berry, Amanda ,Navy, Shannon L ,Kind, Vanessa |
| Nama Majalah/Jurnal | : | Journal of Science Teacher Education |
| Volume / Edisi | : | 30 (No. 1-2) |
| Halaman | : | 63–79 |
| Abstrak | : | Science teacher professional development is complex. Phases in a tea cher’s career necessitate different professional learning opportunities. Furthermore, knowledge bases, practices, and attributes need to be cultivated during these times. For science teachers, it is not always evident how to link professional learning opportunities progressively toward different outcomes, including being a department head, teacher leader, curriculum developer, or even master teacher. In order to spur a discus sion about purposeful teacher learning, we use a theory of transformative learning to examine research pertaining to the professional learning of science teachers. The result is a conceptual framework that suggests that teachers should build their knowledge, practices, and attributes in a way that allows them to realize their potential within specificcommunities. This framework acknowledges that teachers change over time; that knowledge, practices, and attributes are involved in these changes; and that the situated positions of teachers contribute to these changes. Examples associated with this framework are shared in the article to enable educational researchers to approach the study of science teacher development in different ways, which can help guide professional devel opment programming, teacher learning, and potential policy decisions. Most important, this framework offers science teachers a way to consider their own professional growth |
Disentangling Bias and Variance in Election Polls
| Pengarang | : | Houshmand Shirani-Mehr |
| Nama Majalah/Jurnal | : | Journal of the American Statistical Association |
| Volume / Edisi | : | 113 (No. 522) |
| Halaman | : | 607-614 |
| Abstrak | : | It is well known among researchers and practitioners that election polls suffer from a variety of sampling and nonsampling errors, often collectively referred to as total survey error. Reported margins of error typically only capture sampling variability, and in particular, generally ignore nonsampling errors in defining the target population (e.g., errors due to uncertainty in who will vote). Here, we empirically analyze 4221 polls for 608 state-level presidential, senatorial, and gubernatorial elections between 1998 and 2014, all of which were conducted during the final three weeks of the campaigns. Comparing to the actual election outcomes, we find that average survey error as measured by root mean square error is approximately 3.5 percentage points, about twice as large as that implied by most reported margins of error. We decompose survey error into election-level bias and variance terms. We find that average absolute election-level bias is about 2 percentage points, indicating that polls for a given election often share a common component of error. This shared error may stem from the fact that polling organizations often face similar difficulties in reaching various subgroups of the population, and that they rely on similar screening rules when estimating who will vote. We also find that average election-level variance is higher than implied by simple random sampling, in part because polling organizations often use complex sampling designs and adjustment procedures. We conclude by discussing how these results help explain polling failures in the 2016 U.S. presidential election, and offer recommendations to improve polling practice. |
Preservice Science Teachers’ Opportunities for Learning Through Reflection When Planning a Microteaching Unit
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Journal of Science Teacher Education |
| Volume / Edisi | : | 30 (No. 1-2) |
| Halaman | : | 44–62 |
| Abstrak | : | Although microteaching is a common approach to engaging preservice teachers in reflection on teaching in on-campus courses, this reflection is usually carried outasaseparatepart.Weexaminedhowpreservicemiddle school science teachers reflected amid planning a 20-min microteaching unit on sustainable development. Six groups of preservice teachers were video recorded and their conversations transcribed. We used practical epistemology analysis to analyze moments of reflection in these conver sations. The preservice science teachers recurrently engaged in reflection in the course of their planning, which led to changes in perspective concerning important aspects of how to plan teaching that may be considered central for preservice science teachers to learn during their teacher education. Preservice teachers’ reflection was related to the open ness of the task, as they had to make decisions about many different aspects of their teaching. Even aspects that are not on the table in a real world setting, for instance having the possibility of deciding on the age of the target students, led to productive reflection and opportunities for learning. Our results contribute to increased awareness of the possibilities of microteaching for facilitating learning during planning. This may pro vide science teacher educators with better possibilities of supporting their preservice science teachers’ reflective practice. |
Nested Hierarchical Functional Data Modeling and Inference for the Analysis of Functional Plant Phenotypes
| Pengarang | : | Yuhang Xu |
| Nama Majalah/Jurnal | : | Journal of the American Statistical Association |
| Volume / Edisi | : | 113 (No. 522) |
| Halaman | : | 593-606 |
| Abstrak | : | In a plant science Root Image Study, the process of seedling roots bending in response to gravity is recorded using digital cameras, and the bending rates are modeled as functional plant phenotype data. The functional phenotypes are collected from seeds representing a large variety of genotypes and have a three-level nested hierarchical structure, with seeds nested in groups nested in genotypes. The seeds are imaged on different days of the lunar cycle, and an important scientific question is whether there are lunar effects on root bending. We allow the mean function of the bending rate to depend on the lunar day and model the phenotypic variation between genotypes, groups of seeds imaged together, and individual seeds by hierarchical functional random effects. We estimate the covariance functions of the functional random effects by a fast penalized tensor product spline approach, perform multi-level functional principal component analysis (FPCA) using the best linear unbiased predictor of the principal component scores, and improve the efficiency of mean estimation by iterative decorrelation. We choose the number of principal components using a conditional Akaike information criterion and test the lunar day effect using generalized likelihood ratio test statistics based on the marginal and conditional likelihoods. We also propose a permutation procedure to evaluate the null distribution of the test statistics. Our simulation studies show that our model selection criterion selects the correct number of principal components with remarkably high frequency, and the likelihood-based tests based on FPCA have higher power than a test based on working independence. Supplementary materials for this article are available online. |
Supporting ELLs’ Use of Hybrid Language and Argumentation During Science Instruction
| Pengarang | : | - |
| Nama Majalah/Jurnal | : | Journal of Science Teacher Education |
| Volume / Edisi | : | 30 (No. 1-2) |
| Halaman | : | 24–43 |
| Abstrak | : | To bridge the gap for English language learners (ELLs) in science, hybrid language affords the opportunity for students to communicate through various modes, including natural language, visual representa tions, mathematical expressions, and manual-technical operations. The purpose of this study was to investigate how ELLs use hybrid language (a) to demonstrate their knowledge of science and (b) to engage in argumentation. ELLs participated in a summer enrichment program that integrated language, inquiry-based investigations on erosion, and mathematics. The research team qualitatively assessed 15 student notebooks to trace students’ growth in science content as demonstrated by the integration of all 4 modes and the presence of argumentation with embeddedness. The results revealed that 8th grade ELLs increased their use of each mode of hybrid language over time to communicate their understanding of erosion. As expected, some students integrated all modes of hybrid language more fre quently than other students. In addition, argumentation became more evident toward the end of the experience as students used claims and evidence. Students who connected their written claims with visual representations (embeddedness) tended to construct stronger arguments than those who did not make connections between text and visuals. Implications for classroom practices and teacher preparation are discussed. |
Atangs to kuwentos: The power of communal care as decolonial mental health praxis among Pilipinx Americans.
| Pengarang | : | Johnson-Jennings, Michelle; Huyser, Kimberly R.; Collins, Katherine A.; Jessome, Mary G.; Christianson, Traci-lee D.; Chavez, Tamara; Lockhart, Felix J. |
| Nama Majalah/Jurnal | : | American Psychologist |
| Volume / Edisi | : | 80 (No. 4) |
| Halaman | : | 476-493 |
| Abstrak | : | Pilipinx Americans (PAs) are situated at a unique intersection as descendants from colonized peoples living in the diaspora. They endure ongoing deleterious effects of colonization, including mental health (MH) disparities. Simultaneously, PAs live as settlers on Indigenous lands and need to interrogate any complicity in the ongoing colonization of First Nations from what is now called America. To examine their role in decolonial and liberatory MH practices, 12 PA social work scholars and MH practitioners conducted a culturally embedded critical collaborative autoethnography. Consensual qualitative research was used to analyze data from three focus groups. Three domains relevant to decolonial MH praxis among PAs were located. The first domain, disrupting hegemonic views of MH, captures the idea that PA MH conceptions may conflict with western MH services and systems. The second domain, resisting through cultural continuity and survivance, illuminates PAs’ ongoing legacy of enduring cultural and communal practices and resisting colonization despite attempted erasure. The third domain, transforming the MH profession through decoloniality, (re)imagines MH services for and by PAs while simultaneously reckoning with their positionality as diasporic colonial descendants and settlers. Implications and advocacy for culturally embedded practices, trainings, and policies are discussed. |
Semiparametric Estimation of Longitudinal Medical Cost Trajectory
| Pengarang | : | Liang Li |
| Nama Majalah/Jurnal | : | Journal of the American Statistical Association |
| Volume / Edisi | : | 113 (No. 522) |
| Halaman | : | 582-592 |
| Abstrak | : | Estimating the average monthly medical costs from disease diagnosis to a terminal event such as death for an incident cohort of patients is a topic of immense interest to researchers in health policy and health economics because patterns of average monthly costs over time reveal how medical costs vary across phases of care. The statistical challenges to estimating monthly medical costs longitudinally are multifold; the longitudinal cost trajectory (formed by plotting the average monthly costs from diagnosis to the terminal event) is likely to be nonlinear, with its shape depending on the time of the terminal event, which can be subject to right censoring. The goal of this article is to tackle this statistically challenging topic by estimating the conditional mean cost at any month t given the time of the terminal event s. The longitudinal cost trajectories with different terminal event times form a bivariate surface of t and s, under the constraint t ? s. We propose to estimate this surface using bivariate penalized splines in an expectation-maximization algorithm that treats the censored terminal event times as missing data. We evaluate the proposed model and estimation method in simulations and apply the method to the medical cost data of an incident cohort of stage IV breast cancer patients from the Surveillance, Epidemiology, and End Results–Medicare Linked Database. Supplementary materials for this article are available online. |