Self Reflections of Undergraduate Students on Using Web-Supported Counterintuitive Science Demonstrations

Analysis of self-reflections of undergraduate education students in a project involving web-supported counterintuitive science demonstrations is reported in this paper. Participating students (N?=?19) taught science with counterintuitive demonstrations in local elementary school classrooms and used web-based resources accessed via wireless USB adapters. Student reflections to seven questions were analyzed qualitatively using four components of reflection (meeting objectives/perception of learning, dynamics of pedagogy, special needs accommodations, improving teaching) deriving 27 initial data categories and 12 emergent themes. Overall the undergraduates reported meeting objectives, engaging students in pedagogically relevant learning tasks including, providing accommodations to students with special needs, and gaining practice and insight to improve their own teaching. Additional research is needed to arrive at generalizable findings concerning teaching with web-supported counterintuitive science demonstrations in elementary classrooms.     

Shear capacity of reinforced concrete columns strengthened with CFRP sheet

INTRODUCTION There is increased need in recent years for strengthening or rehabilitation of existing reinforced concrete structures adversely affected by overloading, construction material deterioration, seismic loads, structural deformation, etc. An effective method for increasing the shear capacity of reinforced concrete columns is the use of externally bonded carbon fiber reinforced plastic (CFRP) systems (ACI, 2002). FRP systems were first applied to reinforced concrete col-umns i…     

Bolstering the quality and integrity of online collaborative university- level courses via an open Sim standalone server in conjunction with sloodle

The contemporary era provides several challenges which extend from the reconstitution of an innovative knowledge domain and curricula to candidate learning platforms that support online course delivery methods. Educators and scholars on these demands have recently started to rethink alternative ways for the assimilation of the experiential knowledge in three-dimensional (3D) technologically advanced environments, like 3D multi-user virtual worlds. In spite the widespread dissemination and proliferation of novel educational implications by utilizing 3D multi-user virtual worlds combined with the 2D interface of LMS (Learning Management Systems) and the assessment of the effectiveness based on the online course delivery method in a long-term usability is still absent from the international academic literature. This study presents interoperability issues focused on the utilization of the virtual world Open Simulator (Open Sim) in conjunction with Sloodle (Simulation Linked Object Oriented Dynamic Learning Environment) as a free plug-in module. The evaluation of this online learning process according to an empirical research method became possible with the assistance of ninety-five (95) students by two different academic sectors that participated in this project and measured the capabilities and instructional affordances of this platform. The evaluation process was focused on four multi-dimensional parameters (psychological-pedagogical, technical-operational, organizational-financial, and socio-cultural). The study findings based on students’ experiences revealed that both platforms could be sufficiently connected as a unique platform which can increase the users’ learning abilities. This “hybrid” platform can adequately convert the ordinary multi-user virtual world of Open Sim and Sloodle in a common “incubator” of knowledge for online courses at university level. At the end, the instructional affordances and implications for future-driven directions are also discussed.     

Diagnosing Students’ Understanding of the Nature of Models

Students’ understanding of models in science has been subject to a number of investigations. The instruments the researchers used are suitable for educational research but, due to their complexity, cannot be employed directly by teachers. This article presents forced choice (FC) tasks, which, assembled as a diagnostic instrument, are supposed to measure students’ understanding of the nature of models efficiently, while being sensitive enough to detect differences between individuals. In order to evaluate if the diagnostic instrument is suitable for its intended use, we propose an approach that complies with the demand to integrate students’ responses to the tasks into the validation process. Evidence for validity was gathered based on relations to other variables and on students’ response processes. Students’ understanding of the nature of models was assessed using three methods: FC tasks, open-ended tasks and interviews (N?=?448). Furthermore, concurrent think-aloud protocols (N?=?30) were performed. The results suggest that the method and the age of the students have an effect on their understanding of the nature of models. A good understanding of the FC tasks as well as a convergence in the findings across the three methods was documented for grades eleven and twelve. This indicates that teachers can use the diagnostic instrument for an efficient and, at the same time, valid diagnosis for this group. Finally, the findings of this article may provide a possible explanation for alternative findings from previous studies as a result of specific methods that were used.     

Residual stress analysis and bow simulation of crystalline silicon solar cells

The pressure to reduce solar energy costs encourages efforts to reduce the thickness of silicon wafers. Thus, the cell bowing problem associated with the use of thin wafers has become increasingly important, as it can lead to the cracking of cells and thus to high yield losses. In this paper, a systematic approach for simulating the cell bowing induced by the firing process is presented. This approach consists of three processes: (1) the material properties are determined using a nanoidentation test; (2) the thicknesses of aluminum (Al) paste and silver (Ag) busbars and fingers are measured using scanning electron microscopy; (3) non-linear finite element analysis (FEA) is used for simulating the cell bowing induced by the firing process. As a result, the bowing obtained using FEA simulation agrees better with the experimental data than that using the bowing calculations suggested in literature. In addition, the total in-plane residual stress state in the wafer/cell due to the firing process can be determined using the FEA simulation. A detailed analysis of the firing-induced stress state in single crystalline silicon (sc-Si), cast, and edge-defined film-fed growth (EFG) multi-crystalline silicon wafers of different thicknesses is presented. Based on this analysis, a simple residual stress calculation is developed to estimate the maximum in-plane principal stress in the wafers. It is also proposed that the metallization pattern, Ag busbars and fingers screen printed on the front of a solar cell, can be designed using this approach. A practical case of a 3-busbar Si solar cell is presented.     

The Nature of Scientific Practice and Science Education

There is, broadly speaking, an agreement within the international science education community that comprehension of the nature of science (NOS) should be a key element in the scientific literacy of citizens. During the last few decades, several didactic approaches have emerged concerning what and how to teach NOS. Also, one of the basic objectives of science education is for students to become familiar with the skills typical of scientific practice; however, there is little reference to their need to also acquire meta-knowledge about scientific practice (i.e., an understanding of the nature of scientific practice). Among other reasons, this may be due to NOS being essentially identified in most of the predominant proposals with the nature of scientific knowledge. But why not plan the teaching of science to be in tune with real scientific practice for students to learn about the nature of scientific practice at the same time as they are learning science? The answer to this question has given rise to a proposal grounded in ten essential pedagogical principles for the teaching and learning of science in secondary school. These are the principle of formulating questions, the principle of creativity and imagination, the principle of experimentation, the principle of procedural diversity, the principle of errors as opportunity, the principle of modeling, the principle of cooperation and teamwork, the principle of argumentation and discussion, the principle of communication, and the principle of evaluation. The purpose of this article is to present the justification and fundaments of these principles.     

Comparisons of observed process quality in German and American infant/toddler programs

Observed process quality in infant/toddler classrooms was compared in Germany (n = 75) and the USA (n = 219). Process quality was assessed with the Infant/Toddler Environment Rating Scale(ITERS) and parent attitudes about ITERS content with the ITERS Parent Questionnaire (ITERSPQ). The ITERS had comparable reliabilities in the two countries and similar factors were found. Content validity of the ITERS is supported in both countries by similarly high ITERSPQ importance scores. ITERS classroom mean scores are similar (Germany = 3.21; USA = 3.36), but a higher US standard deviation is found. A discriminant analysis revealed differences between countries on a bipolar dimension, with US programs characterized by higher scores on custodial issues while German programs have higher scores on educational aspects. Spearman rank order correlations were completed on ITERSPQ importance scores and observed ITERS scores, showing an association only in the USA. Results are discussed in terms of the parental values and infrastructures found in the two countries.

La qualité de processus observée dans les salles de classe des Enfants/Petits Enfants a été comparée en l’Allemagne (n = 75) et aux Etats‐Unis (n = 219). La qualité de processus a été évaluée avec l’Échelle d’Évaluation de l’Environnement des Enfants/Petits Enfants (ITERS) et les attitudes des parents au sujet du contenu de l’ITERS avec le Questionnaire d’ITERS pour les Parents (ITERSPQ). L’ITERS a eu fiabilités comparables dans les deux pays et des facteurs semblables ont été trouvés. La validité du contentu de l’ITERS est soutenue dans les deux pays par des points sur l’importance d’ITERSPQ pareillement hauts. Les points moyens ITERS de la salle de classe sontsemblables, (Allemagne = 3.21 ; Etats‐Unis = 3.36), mais un écart type plus élevé pour les Etats‐Unis est trouvé. Une analyse discriminante a indiqué des différences entre les pays sur une dimension bipolaire, avec les programmes des Etats‐Unis caractérisés par de points plus hauts sur la question de la garde tandis que les programmes allemands ont de points plus hauts sur des aspects éducatifs. Des corrélations Spearman d’ordre de rang ont été accomplies sur les points d’importance ITERSPQ et on a observé des points d’ITERS montrer une association seulement pour les Etats‐Unis. Des résultats sont discutés en termes de valeurs et infrastructures parentales trouvées dans les deux pays.

La calidad de proceso observada en salas de clase de infantes/niños pequeños fue comparada en Alemania (n = 75) y los E.E.U.U. (n = 219). La calidad de proceso fue determinada con la Escala para Evaluar el Ambiente del Infante/ Niño pequeño (ITERS) y las actitudes de los padres hacia el contenido del ITERS con el Cuestionario ITERS para los Padres (ITERSPQ). El ITERS tenía confiabilidades comparables en los dos países y se encontraron factores similares. La validez del contenido del ITERS es apoyada en ambos países por los puntajes sobre la importancia del ITERSPQ que son semejantemente altos. Los puntajes medios ITERS de la sala de clase son similares, (Alemania = 3.21; E.E.U.U. = 3.36), pero se encuentra una desviación estándar más alta con los E.E.U.U. Un análisis discriminante reveló diferencias entre los países en una dimensión bipolar, con los programas de los E.E.U.U. caracterizados por puntajes más altos en el área de la custodia mientras que los programas alemanes tienen puntajes más altos en los aspectos educativos. Las correlaciones Spearman sobre el orden de rango fueron completadas en los puntajes sobre la importancia de ITERSPQ y se observaron puntajes de ITERS demostrando una asociación solamente en los E.E.U.U. Los resultados se discuten en términos de los valores parentales e infraestructuras encontradas en los dos países.     

Investigating further preservice teachers’ conceptions of multidigit whole numbers: refining a framework

This study was designed to investigate preservice elementary school teachers’ (PSTs’) responses to written standard place-value-operation tasks (addition and subtraction). Previous research established that PSTs can often perform but not explain algorithms and provided a four-category framework for PSTs’ conceptions, two correct and two incorrect. Previous findings are replicated for PSTs toward the end of their college careers, and two conceptions are further analyzed to yield three categories of incorrect views of regrouped digits: (a) consistently as 1 value (all as 1 or all as 10), (b) consistently within but not across contexts (i.e., all as 10 in addition but all as 1 in subtraction), and (c) inconsistently (depending on the task).