Conceitos e técnicas são ensinados em ambientes educacionais e deveriam ser aprendidos; porém, os exames nacionais de larga escala têm mostrado resultados indesejados, evidenciando uma lacuna na aprendizagem dos nossos alunos. Segundo Sanchez (2013), nos cursos de graduação em Ciências Contábeis, os principais erros conceituais cometidos pelos estudantes são: uso equivocado dos conceitos de caixa e competência e erros matemáticos. A definição de erro conceitual é referida na literatura sobre misconceptions (Chi, 1992) em que existe uma apresentação padrão na forma em que o erro desponta e um relacionamento incompatível entre os conceitos novos, a serem aprendidos pelos alunos, e os conceitos prévios, já existentes. Os erros conceituais têm seis características: são robustos, consistentes, persistentes, homogêneos, recapitulados e sistemáticos. Por isso, são difíceis de serem corrigidos. Chi et al (1994) utilizam da teoria da estruturação do conhecimento, em que definem que os conceitos são classificados em categorias ao serem aprendidos. Porém, conceitos que são classificados erroneamente transformam-se em erros conceituais robustos: são difíceis de serem aprendidos, pela dificuldade em transpor o conceito para a categoria adequada. Com base na definição de misconception e da estruturação dos conceitos em categorias, buscou-se entender como os estudantes formam os erros conceituais e, com base nestes tipos de erro encontrados e nas seis características dos padrões de erros, coletamos evidências da formação e superação dos erros por parte dos alunos. Estas evidências nos auxiliaram na criação de uma estratégia de ensino, construída com base na estruturação do conhecimento e, que seja diferente da estratégia \"comum\" de aula de Contabilidade Introdutória, que é o primeiro contato dos estudantes da área de negócios com contabilidade, com intuito de responder a nossa questão de pesquisa: \"Qual o impacto (proporção e sentido) da adoção desta estratégia de ensino baseada em erros conceituais no aprendizado dos estudantes?\" O impacto da estratégia foi motivacional, pois fez os alunos refletirem sobre os erros conceituais, mas insuficiente para aumentar a proporção de acertos nas avaliações realizadas. / Concepts and techniques are taught in educational settings and should be learned; however, large-scale national exams have shown undesirable results, evidencing a learning gap in our students. According to Sanchez (2013), in the undergraduate courses in Accounting, the main misconception made by students are: misuse of concepts of cash and accrual and mathematical errors. The definition of misconception is referred to in the literature (Chi, 1992) in which there is a standard presentation in the form in which the error emerges and an incompatible relationship between the new concepts to be learned by the students and the prior knowledge already existing. Misconception have six characteristics: they are robust, consistent, persistent, homogeneous, recapitulated and systematic. Therefore, they are difficult to correct. Chi et al. (1994) use the theory of knowledge structuring, where they define that concepts are classified into categories when they are learned. However, concepts that are misclassified become robust conceptual errors: they are difficult to learn because of the difficulty in transposing the concept into the appropriate category. Based on the definition of misconception and the structuring of concepts into categories, we sought to understand how students form misconception and, based on these types of errors found and on the six characteristics, we collect evidence of the formation and overcoming of errors on the part of the students. These evidences helped us in creating a teaching strategy, based on the structuring of knowledge and that is different from the \"common\" strategy of First Accounting Class, which is the first contact of the students of the business area with accounting, with In order to answer our research question: \"What is the impact (proportion and signal) of adopting this teaching strategy based on conceptual errors in learning?\" The impact of the strategy was motivational, as it made the students reflect on the conceptual errors, but insufficient to increase the proportion of correctness in the realized evaluations.

Dans cette thèse, j’aborde le problème important de l’estimation de la structure des réseaux complexes, à l’aide de la classe des modèles stochastiques dits réseaux Bayésiens. Les réseaux Bayésiens permettent de représenter l’ensemble des relations d’indépendance conditionnelle. L’apprentissage statistique de la structure de ces réseaux complexes par les réseaux Bayésiens peut révéler la structure causale sous-jacente. Il peut également servir pour la prédiction de quantités qui sont difficiles, coûteuses, ou non éthiques comme par exemple le calcul de la probabilité de survenance d’un cancer à partir de l’observation de quantités annexes, plus faciles à obtenir. Les contributions de ma thèse consistent en : (A) un logiciel développé en langage C pour l’apprentissage de la structure des réseaux bayésiens; (B) l’introduction d’un nouveau "jumping kernel" dans l’algorithme de "Metropolis-Hasting" pour un échantillonnage rapide de réseaux; (C) l’extension de la notion de réseaux Bayésiens aux structures incluant des boucles et (D) un logiciel spécifique pour l’apprentissage des structures cycliques. Notre principal objectif est l’apprentissage statistique de la structure de réseaux complexes représentée par un graphe et par conséquent notre objet d’intérêt est cette structure graphique. Un graphe est constitué de nœuds et d’arcs. Tous les paramètres apparaissant dans le modèle mathématique et différents de ceux qui caractérisent la structure graphique sont considérés comme des paramètres de nuisance. / In this thesis, I address the important problem of the determination of the structure of complex networks, with the widely used class of Bayesian network models as a concrete vehicle of my ideas. The structure of a Bayesian network represents a set of conditional independence relations that hold in the domain. Learning the structure of the Bayesian network model that represents a domain can reveal insights into its underlying causal structure. Moreover, it can also be used for prediction of quantities that are difficult, expensive, or unethical to measure such as the probability of cancer based on other quantities that are easier to obtain. The contributions of this thesis include (A) a software developed in C language for structure learning of Bayesian networks; (B) introduction a new jumping kernel in the Metropolis-Hasting algorithm for faster sampling of networks (C) extending the notion of Bayesian networks to structures involving loops and (D) a software developed specifically to learn cyclic structures. Our primary objective is structure learning and thus the graph structure is our parameter of interest. We intend not to perform estimation of the parameters involved in the mathematical models.

The purpose of this research is to assess the impact of Chinese acquisitions on Italian target firm performance, and explore which characteristics of the acquirer can determine a change of it. First, a Paired-Samples T-test has been applied to appreciate the difference between pre-and post-acquisition performance on 27 sample companies. Secondly, through an OLS regression, the impact of the Chinese acquirers’ characteristics on the performance of Italian target companies has been estimated for the year 2018. In addition, two interviews with managers from one sample company were carried out to complement the quantitative findings with qualitative insight. The results show that the performance of Italian target companies did not change significantly after the acquisition-at least not in the time span of 3 years used for the analysis- in terms of: profitability, solvency and growth. However, job creation slightly increased following the takeover. Furthermore, our findings indicate that, among the Influential factors examined, Chinese acquirers’ prior M&Aexperience in developed countries and the level of relatedness have a significant and positive impact on the performance of Italian target sampled companies. Whereas, being acquired by a Chinese SOE or POE seems to not affect the performance. Lastly, another influential factor raised by our respondents resulted to be the integration strategy implemented by the Chinese acquirer.Indeed, choosing the appropriate integration strategy for the two entities can be crucial for the acquisition success, and ultimately, for the future performance of the target.

The implementation of the National Curriculum Statement in 2006 saw the name of the subject known as Biology change to Life Sciences accompanied by changes in subject content. The curriculum committee excluded systematics as a separate unit from the new outcomes-based Life Sciences curriculum for grades 10 to 12 that was implemented in 2006. Educators had to include aspects of systematics in teaching these concepts without guidance from the curriculum. This posed the question whether mastery of population dynamics and biodiversity is dependent on content of systematics in the context of the new curriculum. The New Content Framework for Life Sciences implemented in 2009 reintroduced systematics as a single unit. This raised the question why systematics has been reintroduced in the Life Sciences curriculum. This study aims to determine the influence the exclusion of systematics as a separate unit from the Life Sciences curriculum, implemented in 2006, had on the teaching of population studies and biodiversity. Data was gathered by evaluating and analysing the relevant curriculum statements, work schedules and content frameworks. Semi-structured interviews were conducted, first in 2008 when systematics was excluded from the curriculum and then in 2009 after the reintroduction. The first interviews dealt with the exclusion of systematics and the second interviews queried the reintroduction of systematics in the New Content Framework. Interviews were conducted with grade 11 Life Sciences educators at two secondary schools and two curriculum developers involved in compiling the Life Sciences curriculum. An expert in systematics and another in ecology were interviewed about the exclusion of systematics. The workbooks of some grade 11 learners were studied. Classroom observations were conducted when the relevant topics were being covered in class. A number of reasons for the exclusion of systematics from the NCS were advanced. These included: there was no population dynamics expert in the curriculum development team, emphasis was placed on outcomes and not content, the academic background of the members of the curriculum team and the difficulty of teaching systematics, perceived to be uninteresting. There was disagreement whether systematics is essential for understanding population dynamics but there is consensus that the study of systematics influences biodiversity and its exclusion left a regrettable void. However, systematics should be taught in a more interesting way. Prior knowledge is important for understanding of certain processes and concepts as well as for the application of practical skills like problem-solving and scientific inquiry. The curriculum does not provide detailed guidance on the content and practical activities to be covered and educators are encouraged to develop their own curriculum and activities. Experienced educators with strong academic backgrounds in animal and plant sciences referred to or used knowledge of systematics in some lessons. In 2009, systematics was reintroduced in the Life Sciences curriculum to ensure that learners understand biodiversity and evolution through natural selection. It provides learners a better foundation to understand similarities and differences in the structure and function of different organisms and body plans and ensures that they use higher-order thinking skills when doing problem-solving and scientific inquiry activities. / Dissertation (MEd)--University of Pretoria, 2010. / Curriculum Studies / unrestricted

Philosophiae Doctor - PhD / This study begins with an ethnographic self-study which allows for a reflection on traditional learning experiences. This study is located in the context of the initial development of dental health professionals within those higher education institutions that endeavour to provide education and training in a rapidly changing context. This context is characterised by the simultaneous need to address the blurring of boundaries and the dichotomies that exist such as the first world and the third world, the developed and the less developed world, the rich and the poor, health and wealth, the private and the public sectors, the formal and the informal sectors, the advantaged and the disadvantaged, the privileged and the underprivileged. The definitions, concepts, theories and principles around curricula and professional development are examined in an effort to extend into discoveries of educational research usually beyond the purview of dental health practitioners, policy makers or higher education specialists involved in training these dental health practitioners. It poses key questions regarding the nature of professional competences within dental health science undergraduate studies and how the curricula are organised around these perceptions of competence. Investigative tools include participant observation, interviews and questionnaires which have included both education deliverers - the teaching staff - and education consumers - the students. The areas of access by students to programmes (input), activities whilst in the programmes (throughput) and their competences at the exit end of the programme (output) are examined. It was found that institutions and programmes are paradoxically positioned declaring missions to be globally competitive and internationally recognised and at the same time wanting to reach out to the population who are disadvantaged and who form a majority. Whilst the needs of the wider community is for basic dental services and primary health care, the resources appear to be geared for producing technologically-superior professionals who will cater for a largely urban and middle class populations. The resources available, particularly human resources, for this training, are going through a critical shortage. Simultaneously demands are being made to challenge the epistemological rationale of the curriculum practice of the training sites at both universities and technikons (now known as universities of technology). These findings reveal that the SAQA demands and the proposed transformation of higher education provided an impetus for schools and departments within universities and technikons and their institutes to look at educational concepts and to transform curricula. This shift was found to be hampered by a variety of causes which included territorial protection, lack of a deep understanding of the education and training concepts and lack of human, physical and financial resources. It was also found that traditional designs of programmes are locked into tribal boundaries which restrict movement beyond these. The boundaries are ring-fenced by historical legacies and practices which confine programmes within these borders and continue to cement the fragmented development of dental health science professionals. The education and training of the different dental health science occupational categories are fragmented between institutes, within institutes and with three separate professional regulating bodies and, seemingly, disjointed functioning national and provincial departments of health and education. This (education and training) is found to be dominated by the traditional mould of teaching, learning and assessment with pockets of change in some schools and departments. Teaching units in the form of subjects, which operate as discrete units and remain entrenched by the habituations of subjects and departments within schools, restricts movement in the competence-based direction. The framework offered by this thesis sets broader and more fluid principles and guidelines which embody the notion of knowledge, skills, attitudes and values and which course designers and educators can utilise so that renewed ways can emerge for their programmes. This allows for a cross over into each other's territories (regulatory, institutional and the health and educational services) that will allow for courses to be designed more holistically and rationally with appropriate transformatory potential.

Some children struggle to learn the academic skill of reading. Providing effective assistance to struggling students, especially to English Language Learners (ELLs), can be a challenge for teachers. The purpose of this study was to examine the impact of childcare programs on the reading achievement of ELLs in kindergarten and first grade. Vygotsky's sociocultural theory along with developmentally appropriate practices constituted the theoretical framework. The overarching research question examined differences in overall reading achievement of ELLs based on the completion of formal childcare programs. A causal-comparative design was used with a cluster sample drawn from a United States federal database of 3,214 ELLs divided into 2 groups: children who participated in formal childcare (FC) programs and those with no formal childcare (NFC). Four independent-samples t tests were performed to compare reading achievement of FC and NFC participants from the fall 2010 kindergarten class (FC n = 1,348, NFC n = 1,414), spring 2011 kindergarten class (FC n = 1,485, NFC n = 1621), fall 2011 first grade class (FC n = 650, NFC n = 698), and spring 2012 first grade class (FC n = 1,482, NFC n = 1,622). Using the Bonferonni method to reduce Type I errors due to familywise analyses, the a priori alpha level decreased to 0.0125. ELL students who participated in formal preschool childcare programs achieved higher scores in reading throughout kindergarten and first grade. Based on these findings, a project was developed for family childcare providers to use to facilitate literacy development. Positive social change may result from ensuring that more children begin kindergarten and first grade with a foundation of reading skills needed for ongoing learning and academic success.

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The present study focuses on developing a relationship between process variables, mechanical properties and post weld microstructure in Friction Stir Welded HSLA 65 steel. Fully consolidated welds can be produced in HSLA 65 steel by PCBN Convex-Scrolled-Shoulder-Step-Spiral (CS4) tool over a wide range of parameters. Microstructures in the nugget center (NC) are dominated by lath bainite and a few polygonal/allotriomorphic grain boundary ferrites. FSW dependent variables are related to FSW independent variables by non-linear relationship. Heat input is identified to be the best parameter index to correlate with microstructures. With increasing heat input, the volume of bainite is reduced, the shape of bainite is more curved and grain/lath size become coarser. A linear relationship was established between heat input and semi-quantitative post-weld microstructures based on the optical microstructures. Further analysis has been applied on the NC to obtain more fundamental understanding of FSW. The new approach via Orientation Imaging Microscopy (OIM) was developed to acquire quantitative microstructural data including bainite lath/packet and prior austenite grain size (PAG). A linear relationship between heat input and quantitative microstructural features in the NC have been established. Mechanical properties exhibits linear relationship with heat input. These correlations can be utilized to determine FSW weld parameter to get desired mechanical properties welds.