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Schwarzer S.,IPN Leibniz Institute for Science and Mathematics Education | Betke A.,Justus Liebig University | Logemann C.,Justus Liebig University | Wickleder M.S.,Justus Liebig University
European Journal of Inorganic Chemistry | Year: 2017

The reaction of elemental rhodium and concentrated sulfuric acid (97 %) at 400 °C leads to red plate-shaped single crystals of Rh2(SO4)3 [trigonal, R3, Z = 6, a = 806.8(1) pm, c = 2204.8(4) pm, V = 1242.8(4) × 106 pm3]. The same reaction carried out at a temperature of 475 °C leads to orange crystals of Rh2(SO4)3·2H2O [orthorhombic, Pnma, Z = 4, a = 920.46(2) pm, b = 1244.47(3) pm, c = 833.37(2) pm, V = 954.61(4) × 106 pm3]. Thermal analysis and X-ray powder diffraction measurements were performed to investigate the decomposition and resulting residues of the compounds. For both compounds the decomposition occurs through two steps and is finished at around 1000 °C at the stage of elemental rhodium. Additionally both sulfates were characterized by means of IR spectroscopy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


Lund T.J.,Oregon Institute of Technology | Pilarz M.,Rowan University | Velasco J.B.,University of Nebraska - Lincoln | Chakraverty D.,IPN Leibniz Institute for Science and Mathematics Education | And 3 more authors.
CBE Life Sciences Education | Year: 2015

Researchers, university administrators, and faculty members are increasingly interested in measuring and describing instructional practices provided in science, technology, engineering, and mathematics (STEM) courses at the college level. Specifically, there is keen interest in comparing instructional practices between courses, monitoring changes over time, and mapping observed practices to research-based teaching. While increasingly common observation protocols (Reformed Teaching Observation Protocol [RTOP] and Classroom Observation Protocol in Undergraduate STEM [COPUS]) at the postsecondary level help achieve some of these goals, they also suffer from weaknesses that limit their applicability. In this study, we leverage the strengths of these protocols to provide an easy method that enables the reliable and valid characterization of instructional practices. This method was developed empirically via a cluster analysis using observations of 269 individual class periods, corresponding to 73 different faculty members, 28 different research-intensive institutions, and various STEM disciplines. Ten clusters, called COPUS profiles, emerged from this analysis; they represent the most common types of instructional practices enacted in the classrooms observed for this study. RTOP scores were used to validate the alignment of the 10 COPUS profiles with reformed teaching. Herein, we present a detailed description of the cluster analysis method, the COPUS profiles, and the distribution of the COPUS profiles across various STEM courses at research-intensive universities. © 2015 T. J. Lund et al.


Neubrand C.,IPN Leibniz Institute for Science and Mathematics Education | Borzikowsky C.,Institute of Medical Informatics and Statistics | Harms U.,IPN Leibniz Institute for Science and Mathematics Education
International Journal of Environmental and Science Education | Year: 2016

Evolutionary theory constitutes the overarching concept in biology. There is hardly any other concept that is more complex, and causes more difficulties in learning and teaching. One instructional approach in optimizing the learning of complex topics is to use worked examples combined with self-explanation prompts that fit to the prior knowledge (knowledge adapted prompts). Especially from cognitive psychological research we know, that prior knowledge is a tremendously relevant factor for learning. However, corresponding studies so far mainly consider the domain specific prior knowledge of high knowledge (expert) versus low knowledge (novice) students. The majority of the learners in a classroom – namely students between these experts and novices - were hardly focused on. These students will be considered here. The aim of our study was to identify how these learners with average prior knowledge can be supported by prompts when learning with worked examples. Using worked examples we analyzed how different types of self-explanation prompts (at novice and/or expert level) affect knowledge acquisition in evolution of learners with average prior knowledge. For determining the prior biological knowledge we used a general biological content knowledge test (GBCK). The learning gain was measured with an evolutionary biological content knowledge test (EBCK). Knowing what type of prompt is most effective for the learners with average knowledge we compared the benefits of this instructional combination between the three knowledge levels: novices, averages, and experts. Results show that for learners with average knowledge, all types of prompts were equally effective. The Matthew effect was not reliable between the knowledge levels. According to our results, learners with average prior knowledge did not require explicit measures of differentiation for learning evolution with prompted worked examples. Nonetheless, for the experts it seems not appropriate to use worked examples with adapted self-explanation prompts. Rather it may be advisable to use another instructional format than worked examples. © 2016 Neubrand, Borzikowsky and Harms.


Schwichow M.,IPN Leibniz Institute for Science and Mathematics Education | Croker S.,Illinois State University | Zimmerman C.,Illinois State University | Hoffler T.,IPN Leibniz Institute for Science and Mathematics Education | Hartig H.,IPN Leibniz Institute for Science and Mathematics Education
Developmental Review | Year: 2016

A core component of scientific inquiry is the ability to evaluate evidence generated from controlled experiments and then to relate that evidence to a hypothesis or theory. The control-of-variables strategy (CVS) is foundational for school science and scientific literacy, but it does not routinely develop without practice or instruction. This meta-analysis summarizes the findings from 72 intervention studies at least partly designed to increase students' CVS skills. By using the method of robust meta-regression for dealing with multiple effect sizes from single studies, and by excluding outliers, we estimated a mean effect size of g = 0.61 (95% CI = 0.53-0.69). Our moderator analyses focused on design features, student characteristics, instruction characteristics, and assessment features. Only two instruction characteristics - the use of cognitive conflict and the use of demonstrations - were significantly related to student achievement. Furthermore, the format of the assessment instrument was identified as a major source of variability between study outcomes. Implications for teaching and learning science process skills and future research are discussed. © 2016 The Authors.


Stains M.,University of Nebraska - Lincoln | Pilarz M.,Rowan University | Chakraverty D.,IPN Leibniz Institute for Science and Mathematics Education
Journal of Chemical Education | Year: 2015

Postsecondary chemistry instructors typically have received little pedagogical training as graduate students and postdoctoral research assistants. Moreover, professional development opportunities are often limited at their own institution. This lack of training has resulted in a gap between the instructional strategies enacted in chemistry courses and the results of discipline-based education research. Members of the Cottrell Scholars Collaborative initiated the New Faculty Workshop (CSC NFW) program in 2012 in order to address this gap. This annual, two-day workshop provides newly-hired chemistry assistant professors from research-intensive universities with training on evidence-based instructional practices. This article presents the results of a longitudinal, quasi-experimental design study that evaluates the short and long-term impacts of the workshop. Online surveys were collected immediately before and after the workshop, as well as one year later from CSC NFW participants and a control group that consisted of newly-hired chemistry faculty who did not participate in the workshop. Surveys measured facultys awareness and use of evidence-based instructional practices, teaching self-efficacy, and beliefs about teaching. Classroom video recordings were also collected during the fall semester following the workshop and two years later. These data were triangulated with the Student Evaluation for Educational Quality (SEEQ) survey, which was collected from students in the observed classrooms. Findings indicate that, in the short-term, the CSC NFW was successful in raising workshop participants self-efficacy, shifting their teaching beliefs toward student-centered teaching, and increasing their use of interactive teaching. Longitudinal data demonstrate that further pedagogical support is required in order for these impacts to be sustained. © 2015 The American Chemical Society and Division of Chemical Education, Inc.


Schreiber M.,IPN Leibniz Institute for Science and Mathematics Education | Engelmann T.,Knowledge Media Research Center
Computers in Human Behavior | Year: 2010

This paper presents an innovative approach for initiating processes of a transactive memory system in newly formed groups of experts collaborating computer-supported in a complex problem-solving task. Our empirical study compared 15 experimental and 15 control groups, each consisting of triads. In the experimental condition, the triads were provided with a tool for fostering knowledge and information awareness, that is, being informed about the knowledge and the underlying information of the collaboration partners in form of digital concept maps. In the control condition, the groups had no access to this tool. Results confirmed the potential of the tool to initiate processes of a transactive memory system: shared agreement of the knowledge of the other group members' knowledge proved to influence group performance positively. In addition, previous findings of the tool's potential to establish knowledge and information awareness and to augment group performance could be replicated. However, the postulated mediating effect of processes of a transactive memory system concerning the impact of knowledge and information awareness on group performance did not reach statistical significance. Aspects for future studies and implications of these findings regarding their practical implementation, for example, in teams of organizations, are discussed. © 2010 Elsevier Ltd. All rights reserved.

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