No description available.

No description available.

This study is a systematic literature review on the role of models and representations in the teaching, learning and understanding of the atom and atomic concepts. The aim of the study is to investigate the role of different visual representations, what models and representations are used in the science classroom, how learners interpret different external representations of the atom, what mental models students construct, and how the representations can be used and designed for meaningful learning and teaching of the atom and atomic concepts.   In this systematic literature review, a combination of different databases was used to search for literature, namely ERIC, Scopus and Google Scholar. Some limiters were used to narrow down the returned results: the articles should be peer-reviewed and be published 1990-01-01 or later. Ten of the returned articles were included for individual analysis in the study.   The results of the study show that students often find concepts of atomic structure difficult and confusing. The abstract microscopic world of atoms cannot be seen with the naked eye, and models are therefore necessary and crucial educational tools for teaching atomic concepts in school. However, when using a model, it is important for the teacher to explain the rules of the model, and the advantages and limitations of the representation must be discussed. Analysis of the included articles revealed three types of representations used to represent atomic phenomena: two-dimensional static diagrams or pictures (e.g. a picture of the atom), three-dimensional videos or simulations (e.g. virtual reality simulations), and visual analogies (e.g. the Bohr planetary model of the atom). The use of simulations and interactive learning environments seem to have a positive effect on students’ learning. One of the studies, described in the articles included for analysis, showed that students appreciated the use of virtual reality simulations, since it made abstract concepts easier to understand when they could be visualized.

In der heutigen Zeit wie auch in der Zukunft steht die Menschheit vor dem Hintergrund einer rapide steigenden Weltbevölkerung und dem Klimawandel vor vielfältigen gesellschaftlichen Herausforderungen. Die Nanowissenschaften bzw. –technologie stellen hierbei ein aktuelles und bedeutendes Forschungsfeld dar, dem ein signifikanter Beitrag zur Bewältigung dieser Problemstellungen zugeschrieben wird. Ungeachtet ihrer großen Bedeutung in Wirtschaft, Wissenschaft und Gesellschaft werden Inhalte aus diesem Themenfeld bislang jedoch nur zögerlich in formale und non-formale Bildungszusammenhänge implementiert. Dies eröffnet eine Reihe von Fragestellungen, allen voran ob dieses Thema für eine Vermittlung außerhalb der Universität geeignet ist und auf welche Weise es didaktisch aufgearbeitet werden kann. Anknüpfend hieran soll in der vorliegenden Arbeit zunächst aus verschiedenen Blickwinkeln untersucht werden, welches Potenzial die Nanotechnologie für eine Vermittlung in Schule, Schülerlabor und Hochschule bietet. Hierbei wird herausgestellt, dass die Nanowissenschaften vielfältige Chancen für den Chemieunterricht bieten.  Aufbauend auf diese Grundlage werden anschließend Beiträge zur fachdidaktischen Konzeptualisierung dieses Themenfeldes vorgestellt. Im Rahmen einer didaktischen Rekonstruktion, welche den methodischen Rahmen der Konzeptualisierung bereitstellt, wird hierbei eine Klärung der Sachstruktur vorgenommen, um die elementaren Konzepte für eine Vermittlung herauszustellen. Von ebenso großer Bedeutung sind darüber hinaus die Perspektiven und Präkonzepte von Lernenden und Lehrenden, welche ebenso wie intrinsische und extrinsische Barrieren für eine unterrichtliche Behandlung empirisch erhoben bzw. identifiziert werden sollen.  Die ermittelten fachlichen Konzepte sowie die Perspektiven der Lernenden und Lehrenden werden schließlich miteinander verknüpft, sodass hieraus Leitlinien für die didaktische Strukturierung abgeleitet werden. Auf dieser Basis werden in dem Hauptteil der vorliegenden Arbeit nun in einem zyklischen Design Konzepte, Unterrichtseinheiten, –materialien sowie Lehrangebote für Schulen, Schülerlabore und Lehrer(fort)bildungen entwickelt, praktisch durchgeführt, evaluiert und weiter optimiert. Die Forschungs- und Entwicklungsarbeit wird dabei systematisch und in Anlehnung an die Basiskonzepte der Chemie erfolgen, um einen optimalen Anschluss an die Bildungsstandards bundesdeutscher Kerncurricula zu gewährleisten.

Despite the growing importance of science and technology in society, school students consider these subjects irrelevant and hard to learn. Teachers must therefore know how to teach science in ways that enhance students’ understanding and interest. This thesis explores various aspects of the teaching and learning of chemical bonding, an important topic in school chemistry that is primarily taught using models. Research has shown that students find chemical bonding difficult to understand, and that the use of models in science education contributes to this difficulty. I therefore investigated teachers’ knowledge of how to teach chemical bonding and ways of developing it to improve students’ understanding. To this end, I analysed chemistry textbooks and teachers’ lesson plans, and conducted semi-structured interviews with teachers about their teaching of chemical bonding. This revealed that the representations of chemical bonding used in textbooks and by teachers can cause students difficulties. The teachers were generally unaware of how these representations might affect students’ understanding, implying that their pedagogical content knowledge (PCK) could be improved. To explore ways of incorporating research findings into teaching practice and developing teachers’ PCK, I conducted a learning study in which three secondary science teachers together explored and reflected on their own teaching practice. CoRe, a method for creating detailed descriptions of what, how, and why specific content is taught, was used to enhance the reflections and make the teachers’ PCK explicit. As a result, the teachers developed their representations of chemical bonding, became more aware of students’ understanding, and were better able to motivate their actions and choices of content and strategies. This thesis shows how professional development can bridge the gap between research and teaching practice, and how teachers’ PCK can be developed to improve students’ understanding. / Many complex real-world phenomena can only be understood using models that make the abstract visible and provide explanations, predictions, descriptions, or simplifications. However, research has shown that students have difficulties understanding models used in science education in general, and particularly chemical bonding models. This thesis examines various aspects of the teaching and learning of chemical bonding, and its presentation in textbooks and by teachers. It is shown that the representations used by teachers and in textbooks can cause students to have difficulties in understanding, which teachers were generally unaware of. Teachers rarely justify their choices specifically to overcome students’ difficulties, suggesting that their knowledge of how to teach chemical bonding could be improved. A learning study in which teachers collaboratively explored and reflected on their own teaching practice significantly improved their presentation of chemical bonding, their awareness of students’ understanding, and their ability to justify their choices. Overall, this work shows that there is a gap between research and teaching practice, and that effective ways of incorporating research results into teaching practice are needed to improve teaching and learning in chemistry.

Os conhecimentos culturais ao redor do sabão de cinzas foram escolhidos como tema de um instrumento hipermídia visando inseri-los em uma sala de aula de Química de nível médio. A inspiração na etnografia foi a via considerada nessa direção, partindo da hipótese de trabalho para a etnociência proposta por D\'Olne Campos (2000) com ênfase em um guia êmico e de acordo com a \"teia de relações\" presente no discurso das produtoras do sabão de cinzas (FOUCAULT, 1986). O instrumento criado reuniu textos, fotografias, vídeos, vozes e perguntas/atividades para a interpretação dos alunos. A investigação em sala de aula buscou perceber a natureza da instrução baseada na inserção de um modo de conhecer distinto nas aulas e seus diálogos com outros conhecimentos. A base teórica da pesquisa procurou integrar a abordagem sociocultural da ação mediada (WERTSCH, 1997) com algumas perspectivas dos estudos (trans) culturais no ensino de ciências, como a noção de travessias de fronteiras culturais (AIKENHEAD, 1996), o modelo genérico para a compreensão holística do aluno de ciências (COSTA, 1995) e a teoria das visões de mundo aplicada na pesquisa no ensino de ciências (COBERN, 1991, 2000a). Os alunos interagiram com o Hipermídia inicialmente em grupos durante quatro aulas, respondendo ao mesmo com receptividade, curiosidade, interesse, exibindo diferentes trânsitos pela narrativa etnográfica e integrando os seus recursos. Os movimentos interpretativos dos alunos se basearam nos diálogos com os colegas de grupo, em pesquisas usando a internet e livros e mediante entrevistas envolvendo a comunidade, havendo evidências de respostas mais produtivas aos processos de significação por pares simétricos. Os alunos manifestaram duas tendências principais de respostas para as perguntas propostas no Hipermídia: o conhecimento químico e os modos de explicar das produtoras do sabão. Essas tendências foram associadas às visões de mundo de ciência escolar dos alunos, levando-os a se inclinarem na direção da ciência que explica (tendência dos alunos do tipo \"Cientista em Potencial\") ou em direções consideradas como sendo mais fáceis de compreender (caso dos \"Outros Alunos Espertos\"). Alunos com pressuposições emocionais, religiosas e utilitárias mostraram trânsitos mais engajados na direção da ciência popular e menor interesse pelas explicações da ciência escolar. Existiram barreiras na direção dos dois conhecimentos envolvidos destacando-se as de linguagem, mas essas foram sendo vencidas pela maioria dos alunos com o desenvolvimento das aulas, através do trabalho colaborativo e do suporte oferecido. A professora desenvolveu 14 aulas a partir da exploração do Hipermídia pelos alunos e foi necessário oferecer um suporte teórico e material para o trabalho da mesma: um texto sobre o construtivismo contextual e o hipermídia das \'Visões de Mundo\', um segundo instrumento criado para promover a interanimação com as vozes dos alunos. Tal suporte implicou em uma mudança do paradigma normal das aulas de Química, sugerindo uma direção contrária à assimilação dos conteúdos pelos alunos e apontando para a compreensão como práxis vinculada à explicitação dos contextos culturais de significação dos conhecimentos envolvidos. Isso conduziu a uma comparação entre conhecimentos, sugerindo que a tarefa da demarcação é difícil e delicada. A comparação entre linguagens e algumas crenças específicas das produtoras do sabão de cinzas, no entanto, pareceram facilitar essa tarefa. / The cultural knowledge around the ash soap was chosen as the theme of a hypermedia instrument aiming to insert it into a Chemistry classroom in the secondary level of education. The ethnographic inspiration was considered in this way according to the work hypothesis to ethnoscience proposed by D\'Olne Campos (2000) with an emics guide emphasis and by considering the \"web of relations\" of the ash soap makers\' discourse (FOUCAULT, 1986). The instrument designed joined texts, photographs, videos, voices and questions/activities to the students\' interpretation. The enquiry tried to perceive the nature of an instruction based on the insertion of a different way of knowing into the classes and its dialogues with other knowledge. The theoretical support attempted to integrate the sociocultural approach to mediated action (WERTSCH, 1997) with some perspectives from the (cross) cultural studies in science education, as the cultural border crossings approach (AIKENHEAD, 1996), the generic model for holistically understanding the science student (COSTA, 1995) and the world view theory applied to the science education research (COBERN, 1991, 2000a). In the beginning, the students interacted with the hypermedia into groups using four classes, answering to it with receptivity, curiosity, showing interest and different border crossings into the ethnographic narrative. Their interpretative movements were based on the dialogues with pairs, in the research using internet and books and by doing interviews with the community. There was evidence that more symmetric pairs respond in a more productive way on their meaning making processes. The students showed two main trends to answer the questions proposed in the hypermedia: the chemistry knowledge and the knowledge of the ash soap makers. These trends were associated to their school science world view, inclining them into the direction of the science that explains (trend of the \"Potencial Scientist\" students) or towards another direction seen as easier to understand (as was the case of the \"Other Smart Kids\" students). Students with emotional, religious and utilitarian presuppositions showed more engaged border crossings to popular science direction and lesser interest for the school chemistry explanations. There were barriers in the direction of both knowledge, highlighting the language ones, but these were figured out by the majority of the students as the teacher developed the classes, through the collaborative work and by the support offered. The teacher developed 14 classes since the students\' finished the hypermedia exploratory work, using different strategies to teach. It was necessary to offer theoretical and material support for her work: a text about the contextual constructivism and the \'World View\' hypermedia, a second instrument designed to promote the interanimation with the students\' voices. This support led to a change in the usual paradigm of the Chemistry classes, pointing to a contrary movement concerned to the students\' assimilation of the contents and towards the comprehension as praxis bridged to the knowledge contexts of meaning explanation. This guided to a comparative work between the knowledge involved, stating that the demarcation task is difficult and delicate. However, this task seemed to be easier to accomplish by comparing languages and through some specific beliefs of the ash soap makers.

<div> <div> <div> <p>Currently there is a need for research that explores students’ understanding of advanced topics in order to improve teaching and learning beyond the context of introductory-level courses. This work investigates students’ reasoning about graphs used in enzyme kinetics. Using semi-structured interviews and a think aloud-protocol, 14 second-year students enrolled in a biochemistry course were provided two graphs to prompt their reasoning, a typical Michaelis-Menten graph and a Michaelis-Menten graph involving enzyme inhibition. Student responses were coded using a combination of inductive and deductive analysis, influenced by the resource-based model of cognition. Results involve a discussion regarding how students utilized mathematical resources to reason about chemical kinetics and enzyme kinetics, such as engaging in the use of symbolic/graphical forms and focusing on surface-level features of the equations/graphs. This work also addresses student conceptions of the particulate-level mechanism associated with competitive, noncompetitive, and uncompetitive enzyme inhibition. Based on the findings of this study, suggestions are made regarding the teaching and learning of enzyme kinetics. </p> </div> </div> </div>

Diante do acentuado crescimento da comunicação científica, tanto em número de artigos publicados em revistas quanto em importância para aqueles que se dedicam à área de Ciências, a capacidade de expressão em linguagem científica tem se tornado uma habilidade valiosa para a formação do graduando em Química. Com o intuito de contribuir no desenvolvimento de tais habilidades, objetivamos neste trabalho elaborar e validar um material didático sobre o tema em foco destinado a alunos de graduação em Química. A elaboração do material foi realizada baseando-se nos fundamentos da pesquisa participativa. Através de reuniões de grupo com alunos de graduação, de pós-graduação e um docente da área de Química foram planejados os objetivos, as estratégias e o conteúdo do material, bem como sua forma de apresentação e organização. Depois de concluído, o material foi validado por novos sujeitos através de um questionário de avaliação. A partir dos debates em grupo foi possível analisar as diferentes visões dos sujeitos da pesquisa sobre diversos temas relacionados à comunicação científica no cenário atual. Vários aspectos do material produzido foram conseqüências das idéias, críticas e sugestões do grupo durante as reuniões. Desta forma, foi possível observar constantes transformações durante sua elaboração, bem como a inclusão de novos conteúdos e abordagens ao longo do texto. Portanto, a pesquisa participativa influenciou consideravelmente o desenvolvimento do referido material, demonstrando ser um importante modelo de construção conjunta do conhecimento. As respostas fornecidas ao questionário de avaliação do material demonstraram sua boa conceituação entre os novos sujeitos da área de Química. Desta forma, foi possível perceber que o material pode ser um importante instrumento didático de apoio para o desenvolvimento de habilidades de comunicação e expressão em linguagem científica. / Considering the accentuated growth of the scientific communication, so much in number of papers published in periodicals as in importance for those who are devoted to the area of Sciences, the capacity of expression in scientific language has been presented as a valuable ability for the formation of the graduation student in Chemistry. With the intention of contributing in the development of such abilities, in the present work, we aimed at elaborating and validating a didactic material about the theme in focus destined for graduation students in Chemistry. The elaboration of the material was accomplished basing on the foundations of the participatory research. Through group meetings with graduation students, masters degree students and a professor of Chemistry, the objectives, the strategies and the contents of the material were drifted, as well as their presentation form and organization. After having ended, the material was validated by new subjects through an evaluation questionnaire. Starting from the group debates, it was possible to analyze the different visions of the subject of the research about several themes related to the scientific communication in the current scenery. Several aspects of the produced material were consequences of the ideas, criticism and suggestions of the group during the meetings. This way, it was possible to observe constant transformations during their elaboration, as well as the inclusion of new contents and approaches along the text. Therefore, the participatory research influenced the development of the referred material considerably, demonstrating to be an important model of united construction of the knowledge. The answers supplied to the evaluation questionnaire of the material demonstrated their good concept among the new subject of the area of Chemistry. This way, it was possible to notice that the material can be an important didactic instrument of supporting for the development of communication abilities and expression in scientific language.

Este trabalho foi desenvolvido na Universidade Federal do Amazonas (UFAM), tendo como sujeitos de pesquisa alunos do curso de Licenciatura em Química. O objetivo foi investigar de que forma uma estratégia didática com o uso de programas computacionais pode contribuir para o aprendizado de conceitos relacionados a equilíbrio ácido-base e para a prática pedagógica de professores em formação inicial. Os programas computacionais e os conceitos químicos foram compreendidos como ferramentas socioculturais. A pesquisa foi desenvolvida em três etapas: 1) acompanhamento o projeto de Ensino de Química, 2) desenvolvimento e aplicação de um curso para os licenciandos e 3) proposta da inserção de um dos programas computacionais no Projeto de Ensino de Química pelos licenciandos. Os instrumentos de coleta de dados utilizados foram entrevistas semiestruturadas, pesquisa documental, fichas de atividade e videogravação. O Projeto Pedagógico do curso e os Planos de Ensino das disciplinas foram os documentos analisados na pesquisa. Os documentos e as transcrições das entrevistas e videogravações foram analisadas por meio da Análise Textual Discursiva à luz da Teoria da Ação Mediada. Observou-se que uma metodologia que emprega recursos tecnológicos no processo de ensino e aprendizagem de química desperta o interesse do licenciando e proporciona diferentes interações dialógicas, contribuindo para a significação de conceitos químicos e para a reflexão sobre a prática pedagógica da qual ele fará uso. Contudo, os dados apontam ainda que o Curso de Licenciatura em Química da UFAM tem contribuído pouco para proporcionar uma interação entre os programas computacionais e os licenciandos a ponto de estimulá-los a se apropriar dessas ferramentas culturais e a inseri-las em suas práticas de ensino. / This thesis was developed in the Federal University of Amazonas (UFAM) and it had students of the Licentiate Degree in Chemistry as investigation subjects. The goal was to investigate how educational strategy using programs could contribute for learning concepts related to acid-base balance and for educational practice of early-career teachers. Programs and chemistry concepts were understood as sociocultural tools. The research was developed in three steps: 1) the follow-up of the Chemistry Education Plan, 2) the development and application of a course to licentiates and 3) the proposal to include one of the programs in the Chemistry Learning Project. Semi structured interviews, documental research, activity files and videorecordings were used as data collect tools. The Pedagogic Project and Subject\'s Education Plans were the analyzed documents in this thesis. The documents, the interview\'s transcriptions and the videorecordings were analyzed by the Discursive Textual Analysis according to the Mediated Action . It was observed that the employment of a methodology that uses technological resources in the chemistry teaching and learning process increases licentiates\' interest and provides different dialogic interactions, contributing to reframe concepts and reflections about the educational practice that they will use. Data also show that the Licentiate Degree in Chemistry of UFAM has contributed little to provide an interaction between computer programs and licentiates so as to stimulate them to appropriate these cultural tools and to insert them into their teaching practices.

Este trabalho foi desenvolvido na Universidade Federal do Amazonas (UFAM), tendo como sujeitos de pesquisa alunos do curso de Licenciatura em Química. O objetivo foi investigar de que forma uma estratégia didática com o uso de programas computacionais pode contribuir para o aprendizado de conceitos relacionados a equilíbrio ácido-base e para a prática pedagógica de professores em formação inicial. Os programas computacionais e os conceitos químicos foram compreendidos como ferramentas socioculturais. A pesquisa foi desenvolvida em três etapas: 1) acompanhamento o projeto de Ensino de Química, 2) desenvolvimento e aplicação de um curso para os licenciandos e 3) proposta da inserção de um dos programas computacionais no Projeto de Ensino de Química pelos licenciandos. Os instrumentos de coleta de dados utilizados foram entrevistas semiestruturadas, pesquisa documental, fichas de atividade e videogravação. O Projeto Pedagógico do curso e os Planos de Ensino das disciplinas foram os documentos analisados na pesquisa. Os documentos e as transcrições das entrevistas e videogravações foram analisadas por meio da Análise Textual Discursiva à luz da Teoria da Ação Mediada. Observou-se que uma metodologia que emprega recursos tecnológicos no processo de ensino e aprendizagem de química desperta o interesse do licenciando e proporciona diferentes interações dialógicas, contribuindo para a significação de conceitos químicos e para a reflexão sobre a prática pedagógica da qual ele fará uso. Contudo, os dados apontam ainda que o Curso de Licenciatura em Química da UFAM tem contribuído pouco para proporcionar uma interação entre os programas computacionais e os licenciandos a ponto de estimulá-los a se apropriar dessas ferramentas culturais e a inseri-las em suas práticas de ensino. / This thesis was developed in the Federal University of Amazonas (UFAM) and it had students of the Licentiate Degree in Chemistry as investigation subjects. The goal was to investigate how educational strategy using programs could contribute for learning concepts related to acid-base balance and for educational practice of early-career teachers. Programs and chemistry concepts were understood as sociocultural tools. The research was developed in three steps: 1) the follow-up of the Chemistry Education Plan, 2) the development and application of a course to licentiates and 3) the proposal to include one of the programs in the Chemistry Learning Project. Semi structured interviews, documental research, activity files and videorecordings were used as data collect tools. The Pedagogic Project and Subject\'s Education Plans were the analyzed documents in this thesis. The documents, the interview\'s transcriptions and the videorecordings were analyzed by the Discursive Textual Analysis according to the Mediated Action . It was observed that the employment of a methodology that uses technological resources in the chemistry teaching and learning process increases licentiates\' interest and provides different dialogic interactions, contributing to reframe concepts and reflections about the educational practice that they will use. Data also show that the Licentiate Degree in Chemistry of UFAM has contributed little to provide an interaction between computer programs and licentiates so as to stimulate them to appropriate these cultural tools and to insert them into their teaching practices.