Survival analysis for Hispanic ELL students’ access to postsecondary schools: discrete model or Cox regression?

Survival analysis is an advanced statistical method to investigate the occurrence and the timing of an important event such as school access, dropout, and graduation in a longitudinal framework. The aim of our study is to provide practical guidelines for empirical researchers in choosing an appropriate survival analysis model. For this goal, this study chose two major survival analytical models of a discrete-time hazard model and a Cox regression model and compared analytical outcomes considering time metrics, as well as sample sizes and censoring proportions. In the analytical model, the combined specifications of varying factors using two models were adopted to analyse the Educational Longitudinal Study of 2002. We chose the college access of Hispanic English Language Learners to understand the importance of adopting a proper survival model to examine the educational outcome in the educational context. Importantly, we considered the hazard probability for the target event in the model specification which is a fundamental yet often neglected component of survival analysis. We recommended discrete models for the cases with a smaller number of time points, larger time metrics, larger sample size, and smaller proportions of censored observations.     

Tools for Reflection: Video-Based Reflection Within a Preservice Community of Practice

Current reform in science education calls for teachers to understand student thinking within a lesson to effectively address students’ needs (NRC in A framework for K-12 science education: practices, crosscutting concepts, and core ideas. National Academy Press, Washington, DC, 2012; NRC in Guide to implementing the Next Generation Science Standards. The National Academies Press, Washington, DC, 2015). This study investigates how to scaffold preservice teachers with learning to attend to students’ thinking for the purpose of guiding curricular decisions. The study focuses on one team teaching a science unit during their early field experience. We sought to understand how participants’ thoughts and abilities changed through participation in a moderated community of practice using video of their own teaching as a reflective tool. We examined how these changes affected both their classroom practice and their decision-making for future lessons. Evidence shows growth in participants’ ability to identify opportunities to elicit, assess, and use students’ thinking to guide instructional decisions. Implications for use of the approach used in this study to begin developing novice teachers’ pedagogical content knowledge for teaching science are discussed.     

How Is Intuitive Thinking Shared and Elaborated During Small-Group Problem-Solving Activities on Thermal Phenomena?

Research in Science Education - In the process of problem solving, intuitive thinking leads to findings that go beyond gaps and plays a decisive role in problem solving. Considering that problems...     

Exploring the nature of associations between educators’ knowledge and their emergent literacy classroom practices

Reading and Writing - Educators’ content knowledge is considered a key determinant of classroom practices and thus children’s learning. In this study, we examine the nature of...     

Improved antioxidative and cytotoxic activities of chamomile (<Emphasis Type="Italic">Matricaria chamomilla</Emphasis>) florets fermented by <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> KCCM 11613P

Antioxidative and cytotoxic effects of chamomile (Matricaria chamomilla) fermented by Lactobacillus plantarum were investigated to improve their biofunctional activities. Total polyphenol (TP) content was measured by the Folin-Denis method, and the antioxidant activities were assessed by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and β-carotene bleaching method. AGS, HeLa, LoVo, MCF-7, and MRC-5 (normal) cells were used to examine the cytotoxic effects by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay. The TP content of fermented chamomile reduced from 21.75 to 18.76 mg gallic acid equivalent (mg GAE)/g, but the DPPH radical capturing activity of fermented chamomile was found to be 11.1% higher than that of nonfermented chamomile after 72 h of fermentation. Following the β-carotene bleaching, the antioxidative effect decreased because of a reduction in pH during fermentation. Additionally, chamomile fermented for 72 h showed a cytotoxic effect of about 95% against cancer cells at 12.7 mg solid/ml of broth, but MRC-5 cells were significantly less sensitive against fermented chamomile samples. These results suggest that the fermentation of chamomile could be applied to develop natural antioxidative and anticancer products.     

Some uneasy inquiries into ID expert systems

Alternative approaches to developing software automating instructional development are described in this article. Information management and expert system approaches are compared. General assumptions underlying the development of all authoring tools, including conventional authoring systems, and additional assumptions underlying the development of expert ID tools are identified. Questions are raised concerning the viability of ID automation tools. It is argued that conventional authoring systems may not be as inadequate or inferior as ID expert system developers have claimed, and that of two approaches to ID automation, tools emphasizing information management are probably most useful. Information management tools, however, still may be inappropriate in some contexts.     

Effect of encoding instructions on children's spatial and color memory: is there evidence for automaticity?

This experiment is concerned with assessing whether there is evidence for the automatic processing of spatial and color information by children and with the development of control of encoding operations. First, third, and fifth graders viewed pictures of simple objects that varied in color (red or green) and spatial location (left or right). Subjects were instructed to encode (a) only the item, (b) the item and its color, (c) the item and its position, (d) the item, its color, and its position. The data yielded evidence for nonchance incidental memory of spatial, but not color, information. The data also suggested that children at all age levels were able to control their encoding operations similarly, as there was no evidence for an interaction of development with encoding instructions. These findings are discussed with respect to a model for automatic encoding processes and work on memory for central and incidental information.     

Teaching about complex systems is no simple matter: building effective professional development for computer-supported complex systems instruction

The recent next generation science standards in the United States have emphasized learning about complex systems as a core feature of science learning. Over the past 15 years, a number of educational tools and theories have been investigated to help students learn about complex systems; but surprisingly, little research has been devoted to identifying the supports that teachers need to teach about complex systems in the classroom. In this paper, we aim to address this gap in the literature. We describe a 2-year professional development study in which we gathered data on teachers’ abilities and perceptions regarding the delivery of computer-supported complex systems curricula. We present results across the 2 years of the project and demonstrate the need for particular instructional supports to improve implementation efforts, including providing differentiated opportunities to build expertise and addressing teacher beliefs about whether computational-model construction belongs in the science classroom. Results from students’ classroom experiences and learning over the 2 years are offered to further illustrate the impact of these instructional supports.