O ensino da leitura e da escrita no 1º ano de escolaridade: os resultados dos alunos em leitura

Tese de Doutoramento em Psicologia Aplicada, Área de especialidade Psicologia EducacionalO presente estudo teve como objetivo caracterizar as práticas de ensino da linguagem escrita em Portugal e perceber o seu impacto na aquisição da leitura no final do 1º ano de escolaridade. A primeira etapa deste estudo correspondeu a um estudo descritivo e comparativo com o realizado por Fijalkow (2003) em França. A partir da resposta a um questionário de 883 professores foi possível verificar que os professores dos dois países se aproximam no que diz respeito aos aspetos metodológicos do ensino da leitura e à avaliação da leitura e da escrita dos alunos. Contudo, os professores portugueses dizem utilizar com maior frequência do que os professores franceses, atividades a partir de livros infantis, outros materiais para além do manual e diferentes propostas de escrita. Na segunda etapa deste estudo, o questionário utilizado foi validado através da sua estrutura fatorial e foram utilizados os fatores revelados para a realização de uma análise hierárquica de clusters. Esta análise revelou três grupos de professores: a) um grupo de professores que centra as suas práticas no ensino do código da linguagem escrita (unidades curtas); b) um grupo que realça a construção de significado na interação com o material escrito (unidades longas); c) e um grupo de professores que reúne nas suas práticas características de ambos os grupos referidos anteriormente (unidades diversificadas). A terceira etapa realizada diz respeito à validação das respostas do questionário através da observação de sala de aula. Foram selecionados 5% dos professores de cada um dos três grupos constituídos (N=42). Cada professor foi observado duas vezes durante 60 minutos em situações escolhidas por si como situações privilegiadas para o ensino da linguagem escrita. Através da utilização de uma grelha de observação que divide as atividades desenvolvidas em atividades que remetem para o código ou para o significado, foi possível confirmar as respostas ao questionário para 55% dos professores participantes. No sentido de perceber o impacto das práticas dos professores na aquisição da leitura dos alunos foram selecionados os professores cujas observações foram coincidentes com as respostas ao questionário e avaliados os seus alunos com recurso a três provas de leitura: leitura de palavras isoladas, decisão lexical e compreensão. Participaram 461 alunos distribuídos pelos três grupos referidos anteriormente. Através da realização de uma MANCOVA, controlando a escolaridade das mães dos alunos, verificou-se que os alunos do grupo unidades diversificadas obtêm melhores resultados em todas as provas do que os alunos dos outros dois grupos. Foi ainda possível constatar que não existiram diferenças de desempenho entre os alunos do grupo unidades curtas e os alunos do grupo unidades longas.ABSTRACT: The present study aimed to characterize the teaching practices of written language and understand its impact on reading acquisition by the end of 1st grade. The first step of this study was a descriptive and comparative study to the one conducted by Fijalkow (2003) in France. Based on questionnaire answers of 883 teachers, we found that teachers from both countries have similar approaches regarding methodological aspects of teaching of reading and students’ assessment of reading and writing abilities. However, Portuguese teachers stated that they use more frequently activities from children's literature, other materials besides the manual and different writing proposals than French teachers. In the second step of the study, the questionnaire was validated through its factorial structure and the factors disclosed were used to perform a hierarchical cluster analysis. This analysis revealed three groups of teachers: a) a group of teachers who focus its practices in teaching the code of written language (short units), b) a group that emphasizes the construction of meaning in interaction with the written material (long units), c) and a group of teachers who gathered in their practices characteristics of both groups mentioned above (diversified units). The third step concerns the validation of the questionnaire answers through classroom observation. 5% of the teachers in each of the three groups were selected (N=42). Each teacher was observed twice during 60 minutes in situations identified by them as privileged situations for teaching written language. Using an observation grid which divides the activities conducted in code-activities or the meaning-activities it was possible to confirm questionnaire answers for 55% of the participating teachers. In order to understand the impact of teachers’ practices in students reading acquisition, teachers whose observations were coincident with the questionnaire answers were selected and their students were evaluated using three reading tests: single words reading, lexical decision task and comprehension task. Participants were 461 students distributed through the three groups previously mentioned. By conducting a MANCOVA, controlling mothers’ education level, we concluded that students in the diversified unit group obtain better results in all reading tests than students from the other groups. It was also possible to confirm that there were no differences in performance between students of the short units group and students of the long units group.Tese de Doutoramento em Psicologia Aplicada, Área de especialidade Psicologia EducacionalApoio financeiro da Fundação para a Ciência e Tecnologia (SFRH/BD/64630/2009

METRIC SCALE CALCULATION FOR VISUAL MAPPING ALGORITHMS

Visual SLAM algorithms allow localizing the camera by mapping its environment by a point cloud based on visual cues. To obtain the camera locations in a metric coordinate system, the metric scale of the point cloud has to be known. This contribution describes a method to calculate the metric scale for a point cloud of an indoor environment, like a parking garage, by fusing multiple individual scale values. The individual scale values are calculated from structures and objects with a-priori known metric extension, which can be identified in the unscaled point cloud. Extensions of building structures, like the driving lane or the room height, are derived from density peaks in the point distribution. The extension of objects, like traffic signs with a known metric size, are derived using projections of their detections in images onto the point cloud. The method is tested with synthetic image sequences of a drive with a front-looking mono camera through a virtual 3D model of a parking garage. It has been shown, that each individual scale value improves either the robustness of the fused scale value or reduces its error. The error of the fused scale is comparable to other recent works

Biobased chiral semi-crystalline or amorphous high-performance polyamides and their scalable stereoselective synthesis

The use of renewable feedstock is one of the twelve key principles of sustainable chemistry. Unfortunately, bio-based compounds often suffer from high production cost and low performance. To fully tap the potential of natural compounds it is important to utilize their functionalities that could make them superior compared to fossil-based resources. Here we show the conversion of (+)-3-carene, a by-product of the cellulose industry into ε-lactams from which polyamides. The lactams are selectively prepared in two diastereomeric configurations, leading to semi-crystalline or amorphous, transparent polymers that can compete with the thermal properties of commercial high-performance polyamides. Copolyamides with caprolactam and laurolactam exhibit an increased glass transition and amorphicity compared to the homopolyamides, potentially broadening the scope of standard polyamides. A four-step one-vessel monomer synthesis, applying chemo-enzymatic catalysis for the initial oxidation step, is established. The great potential of the polyamides is outlined