Comparison of Variable Selection Methods

Use of classic variable selection methods in public health research is quite common. Many criteria, and various strategies for applying them, now exist including forward selection, backward elimination, stepwise selection, best-subset selection and so on, but all suffer from similar drawbacks. Chief among them is a failure to account for the uncertainty contained in the model selection process. Ignoring model uncertainty can cause several serious problems. Variance estimates are generally underestimated, p-values are generally inflated, prediction ability is overestimated, and results are not reproducible in another dataset. Modern variable selection methods have become increasingly popular, especially in applications of high-dimensional or sparse data. Some of these methods were developed to address the short-comings of classic variable selection methods, such as backward elimination and stepwise selection methods. However, it remains unclear how modern variable selection methods behave in a classical, meaning non-high-dimensional, setting. A simulation study investigates the estimation, predictive performance and variable selection capabilities of three representative modern variable selection methods: Bayesian model averaging (BMA), stochastic search variable selection (SSVS), and the adaptive lasso. These three methods are considered in the setting of linear regression with a single variable of interest which is always included in the model. A second simulation study compares BMA to classical variable selection methods, including backward elimination, two-stage method, and change-in-effect method in the setting of logistic regression. Additionally, the data generated in both simulation studies closely mimic a real study and reflect a realistic correlation structure between potential covariates. Sample sizes ranging from 150 to 20000 are investigated. BMA is demonstrated in an example building a predictive model using data from the China Health and Nutrition Survey.Doctor of Public Healt

Understanding Life: Senior Perspectives in Creative Writing

Although high school is meant to prepare students for the real world, it is difficult to determine what knowledge about life students possess at graduation. Learning about how seniors understand and think about life experiences provides educators with greater knowledge of how to meet their maturing needs. This presentation examines how seniors from a Creative Writing class view life themes that came across through their writing. This study was completed using a qualitative self-study approach and included varying data collection methods, such as field notes, informal classroom discussions, and student work. Research has shown that student conceptions of life experiences are varied but developing during senior year. The findings indicate that students benefit from collective discussion since it promotes sharing varied experiences, knowledge, and beliefs. The findings of this study suggest the values of understanding senior beliefs so that educators can widen student perspectives in a safe environment

Snails? Incorporating the Nature of Science and Primary Literature into the High School Biology Classroom

In the high school Biology classroom, science is taught to be fixed, unchanging, and uninteresting to students. By incorporating the Nature of Science and primary literature articles into the science classroom, students can delve deeper into the ever-changing biology curriculum while also becoming a part of the scientific community. Teachers who incorporate these aspects into their academic teaching are finding that students are retaining the curriculum as well as probing deeper into the content by asking more thought-provoking questions (Handler & Duncan, 2006; Brill & Yarden, 2003). In this literature review of educational research, I explored how incorporating the Nature of Science and primary research articles benefitted high school biology students. Based upon the literature, I have developed lesson plans that integrate the Nature of Science into the high school biology classroom

The School Library Can Do More to Counteract Homophobia

This paper discusses the pervasiveness of homophobia in our culture and its impact on lesbian, gay, bisexual, transgender, and questioning (LGBTQ) teenagers. It argues that teacher-librarians can support LGBTQ teens by collecting and promoting young adult literature that portrays positive, realistic images of the LGBTQ community. It presents the findings of two studies - one that examined the library collections in North Carolina high schools for the inclusion of LGBTQ-themed titles and one that investigated the content of ten journals that are frequently read by teacher-librarians for articles about LGBTQ issues and collection development published since 2006. Results revealed that high school teacher-librarians are under-collecting LGBTQ-themed titles. Although 5.9 percent of American high school students identify as gay, lesbian, or bisexual, LGBTQ-themed collections in school libraries are minimal. Additionally, LGBTQ issues are rarely addressed in the scholarly journals. The paper concludes with recommendations to assist teacher-librarians in supporting LGBTQ students

Emerging Writers Learn to Revise and Edit

Writing instruction at the early elementary-level has often been reduced to one-size-fits-all prompts, which encourage limited student engagement or creativity. In response to this, many elementary classrooms have seen a push for workshop models that teach students to think of writing as a process. Through a modified Writers’ Workshop model, this study investigates first grade students and their journey through the revising and editing stages of the process. This three month study includes qualitative data collection methods such as field notes and student work samples. The findings of this study suggest that although revising and editing may seem a daunting task for emerging writers, a combination of explicit group lessons, peer conferencing, and checklists can guide students to look at their own writing with a more critical eye. These results suggest the importance of providing writing instruction that allows for more student involvement and peer interaction

Connecting Through Circles: A Playbook for Cultivating Well-Being Between Wharton Women Alumni

The Wharton Women\u27s Circles (WWC) at the University of Pennsylvania is a ground-breaking alumnae program founded in 2019 with a mandate to cultivate meaningful connections. The Circles, led by facilitators, provide working women a safe space to gather in an environment of support and encouragement. Through this process, women look to build community, confidence, inspiration, and produce desired results across personal and professional domains. Leveraging research in Positive Psychology, our team developed five facilitator-led sessions, encompassed in an adaptable ‘Playbook’ to support facilitators, engage participants, and drive discussions. The Playbook aims to accomplish three goals: (1) Amplify participant connection and well-being (2) Address survey feedback and the desire for more formal programming and structured conversations; and (3) Provide resources to enable future growth and scalability. The Playbook’s five facilitator-led sessions include: Know Your Strengths, Well-Being 101, Fostering Strong Relationships, Struggling Well, and Positive Transitions. We suggest measuring the Playbook’s efficacy through mixed qualitative and quantitative metrics

Speaking vocabulary of first grade children

Thesis (Ed.M.)--Boston Universit

Weight Gain Trajectories Associated With Elevated C‐Reactive Protein Levels in Chinese Adults

BACKGROUND: Recent longitudinal work suggests that weight change is an important risk factor for inflammation across the full range of BMI. However, few studies have examined whether the risk of inflammation differs by patterns of weight gain over time. Using latent class trajectory analysis, we test whether patterns of weight gain are associated with elevated high-sensitivity C-reactive protein (hs-CRP 2-10 mg/L). METHODS AND RESULTS: Data come from China Health and Nutrition Survey (CHNS) participants (n=5536), aged 18 at baseline to 66 years in 2009, with measured weight over 18 years. Latent class trajectory analysis was used to identify weight-change trajectories in 6 age and sex strata. Multivariable general linear mixed-effects models fit with a logit link were used to assess the risk of elevated hs-CRP across weight trajectory classes. Models were fit within age and sex strata, controlling for baseline weight, adult height, and smoking, and included random intercepts to account for community-level correlation. Steeper weight-gain trajectories were associated with greater risk of elevated hs-CRP compared to more moderate weight-gain trajectories in men and women. Initially high weight gain followed by weight loss was associated with lower risk of elevated hs-CRP in women aged 18 to 40. CONCLUSIONS: Latent class trajectory analysis identified heterogeneity in adult weight change associated with differential risk of inflammation independently of baseline weight and smoking. These results suggest that trajectories of weight gain are an important clinical concern and may identify those at risk for inflammation and the development of cardiometabolic disease

Characterizing Long-Term Patterns of Weight Change in China Using Latent Class Trajectory Modeling

BackgroundOver the past three decades, obesity-related diseases have increased tremendously in China, and are now the leading causes of morbidity and mortality. Patterns of weight change can be used to predict risk of obesity-related diseases, increase understanding of etiology of disease risk, identify groups at particularly high risk, and shape prevention strategies.MethodsLatent class trajectory modeling was used to compute weight change trajectories for adults aged 18 to 66 using the China Health and Nutrition Survey (CHNS) data (n = 12,611). Weight change trajectories were computed separately for males and females by age group at baseline due to differential age-related patterns of weight gain in China with urbanization. Generalized linear mixed effects models examined the association between weight change trajectories and baseline characteristics including urbanicity, BMI category, age, and year of study entry.ResultsTrajectory classes were identified for each of six age-sex subgroups corresponding to various degrees of weight loss, maintenance and weight gain. Baseline BMI status was a significant predictor of trajectory membership for all age-sex subgroups. Baseline overweight/obesity increased odds of following ‘initial loss with maintenance’ trajectories. We found no significant association between baseline urbanization and trajectory membership after controlling for other covariates.ConclusionTrajectory analysis identified patterns of weight change for age by gender groups. Lack of association between baseline urbanization status and trajectory membership suggests that living in a rural environment at baseline was not protective. Analyses identified age-specific nuances in weight change patterns, pointing to the importance of subgroup analyses in future research