A Didactic Sequence of Elementary Geometric Optics Informed by History and Philosophy of Science     

Paulo Maurício  Bianor Valente  Isabel Chagas 《International Journal of Science and Mathematics Education》2017,15(3):527-543

The concepts and instruments required for the teaching and learning of geometric optics are introduced in the didactic process without a proper didactic transposition. This claim is secured by the ample evidence of both wide- and deep-rooted alternative concepts on the topic. Didactic transposition is a theory that comes from a reflection on the teaching and learning process in mathematics but has been used in other disciplinary fields. It will be used in this work in order to clear up the main obstacles in the teaching-learning process of geometric optics. We proceed to argue that since Newton’s approach to optics, in his Book I of Opticks, is independent of the corpuscular or undulatory nature of light, it is the most suitable for a constructivist learning environment. However, Newton’s theory must be subject to a proper didactic transposition to help overcome the referred alternative concepts. Then is described our didactic transposition in order to create knowledge to be taught using a dialogical process between students’ previous knowledge, history of optics and the desired outcomes on geometrical optics in an elementary pre-service teacher training course. Finally, we use the scheme-facet structure of knowledge both to analyse and discuss our results as well as to illuminate shortcomings that must be addressed in our next stage of the inquiry.  相似文献   

Career plans of final-year South African student teachers: migration to ‘greener pastures’?     

J. J. R. de Villiers 《Africa Education Review》2017,14(3-4):212-229

Teacher loss due to migration is a global phenomenon that impacts both developed and developing nations the world over. The aim of this study was to find out about the career plans of final-year South African student teachers. A group of final-year Bachelor of Education student teachers from a South African university responded to a questionnaire on intra- and intercontinental migration. The responses were analysed quantitatively and/or qualitatively. The findings showed that 79% of the students indicated that they would be teaching in South Africa, 8% were planning to teach in another country, while 8% were undecided. More than a third of the students (38%) said that they would like to teach in another country in five years’ time. Just more than a quarter of the students (27%) preferred Australia as a destination country. The student teachers’ most important motive to teach in a foreign country was the opportunity to travel, followed by earning a higher salary, and professional development. The student teachers indicated that their most important migration needs before leaving South Africa were information about health care, accommodation, and banking assistance.  相似文献   

Electrical lysis of cells for detergent-free droplet assays     

N. de Lange  T. M. Tran  A. R. Abate 《Biomicrofluidics》2016,10(2)

Efficient lysis is critical when analyzing single cells in microfluidic droplets, but existing methods utilize detergents that can interfere with the assays to be performed. We demonstrate robust cell lysis without the use of detergents or other chemicals. In our method, cells are exposed to electric field immediately before encapsulation in droplets, resulting in cell lysis. We characterize lysis efficiency as a function of control parameters and demonstrate compatibility with enzymatic assays by measuring the catalysis of β-glucosidase, an important cellulase used in the conversion of biomass to biofuel. Our method enables assays in microfluidic droplets that are incompatible with detergents.  相似文献   

The responsibility gap: Ascribing responsibility for the actions of learning automata     

Andreas?MatthiasEmail author 《Ethics and Information Technology》2004,6(3):175-183

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Brazil in the Age of Electronic Commerce     

Paulo Bastos Tigre 《The Information Society》2003,19(1):33-43

E-commerce is growing rapidly in Brazil, led by information-intensive and transaction-intensive sectors such as finance, manufacturing, and retail/wholesale. However, Brazil's highly uneven income distribution is a major barrier for B2C diffusion. Government policies have emphasized promotional or enabling initiatives such as e-procurement, tax filings, and providing Internet access to social institutions. E-commerce legislation is just now being developed, and decisions on taxation are being negotiated in the context of international agreements. E-commerce raises issues for Brazil in terms of its relationship to the global economy. Although most online purchases involve imported goods, e-commerce also offers opportunities to participate in international value chains.  相似文献   

Trusting Virtual Trust   总被引：2，自引：0，他引：2  

Paul?B.?de?LaatEmail author 《Ethics and Information Technology》2005,7(3):167-180

Can trust evolve on the Internet between virtual strangers? Recently, Pettit answered this question in the negative. Focusing on trust in the sense of ‘dynamic, interactive, and trusting’ reliance on other people, he distinguishes between two forms of trust: primary trust rests on the belief that the other is trustworthy, while the more subtle secondary kind of trust is premised on the belief that the other cherishes one’s esteem, and will, therefore, reply to an act of trust in kind (‘trust-responsiveness’). Based on this theory Pettit argues that trust between virtual strangers is impossible: they lack all evidence about one another, which prevents the imputation of trustworthiness and renders the reliance on trust-responsiveness ridiculous. I argue that this argument is flawed, both empirically and theoretically. In several virtual communities amazing acts of trust between pure virtuals have been observed. I propose that these can be explained as follows. On the one hand, social cues, reputation, reliance on third parties, and participation in (quasi-) institutions allow imputing trustworthiness to varying degrees. On the other, precisely trust-responsiveness is also relied upon, as a necessary supplement to primary trust. In virtual markets, esteem as a fair trader is coveted while it contributes to building up one’s reputation. In task groups, a hyperactive style of action may be adopted which amounts to assuming (not: inferring) trust. Trustors expect that their virtual co-workers will reply in kind while such an approach is to be considered the most appropriate in cyberspace. In non-task groups, finally, members often display intimacies while they are confident someone else ‘out there’ will return them. This is facilitated by the one-to-many, asynchronous mode of communication within mailing lists.  相似文献   

Do training institutions learn from experience?     

Claudio de Moura Castro 《International Journal of Educational Development》2011

This essay is concerned with organisational learning and, in particular, policy learning. Sometimes, organisations learn; sometimes they do not. Sometimes they use their acquired knowledge, but this is, not always the case.  相似文献   

Cognitive and environmental predictors of early literacy skills     

Davidse NJ  de Jong MT  Bus AG  Huijbregts SC  Swaab H 《Reading and writing》2011,24(4):395-412

Not all young children benefit from book exposure in preschool age. It is claimed that the ability to hold information in mind (short-term memory), to ignore distraction (inhibition), and to focus attention and stay focused (sustained attention) may have a moderating effect on children’s reactions to the home literacy environment. In a group of 228 junior kindergarten children with a native Dutch background, with a mean age of 54.29 months (SD = 2.12 months), we explored therefore the relationship between book exposure, cognitive control and early literacy skills. Parents filled in a HLE questionnaire (book sharing frequency and an author recognition checklist as indicator of parental leisure reading habits), and children completed several tests in individual sessions with the researcher (a book-cover recognition test, PPVT, letter knowledge test, the subtests categories and patterns of the SON, and cognitive control measures namely digit span of the KABC, a peg tapping task and sustained attention of the ANT). Main findings were: (1) Children’s storybook knowledge mediated the relationship between home literacy environment and literacy skills. (2) Both vocabulary and letter knowledge were predicted by book exposure. (3) Short-term memory predicted vocabulary over and above book exposure. (4) None of the cognitive control mechanisms moderated the beneficial effects of book exposure.  相似文献   

Patterns of contingent teaching in teacher-student interaction     

Janneke van de Pol  Monique VolmanJos Beishuizen 《Learning and Instruction》2011,21(1):46-57

The present study aimed at investigating the process of scaffolding in a naturalistic setting with focus on a key aspect of scaffolding, namely contingency. Three Social Studies teachers in innovative prevocational schools were observed and interviewed. A coding scheme for the measurement of scaffolding was developed which revealed different patterns of contingent and non-contingent teaching amongst the teachers. In general these teachers of innovative schools showed little contingent teaching. Not adapting the support to students' current understanding and barely diagnosing the students' understanding appeared to be characteristic of this scarcity of non-contingent teaching.  相似文献   

Understanding the association between future time perspective and self-regulated learning through the lens of self-determination theory   总被引：1，自引：0，他引：1  

Jerissa de Bilde  Maarten Vansteenkiste  Willy Lens 《Learning and Instruction》2011,21(3):332-344

The present cross-sectional research examined a process underlying the positive association between holding an extended future time perspective (FTP) and learning outcomes through the lens of self-determination theory. High school students and university students (N = 275) participated in the study. It was found that students with an extended FTP regulated their study behaviour on the basis of several internal motives, including feelings of guilt and shame (introjected regulation), personal conviction (identified regulation) and interest (intrinsic motivation). The association with identified regulation was strongest and the association with intrinsic motivation fell below significance when controlling for identified regulation. Moreover, introjected and identified regulation emerged as mediators accounting for the association between FTP and cognitive processing. Further, to the extent that FTP engenders an internally pressuring mode of regulation it was found to be indirectly negatively associated with determination/metacognitive strategy use. In contrast to FTP, a present fatalistic and present hedonic time-orientation yielded more negative motivational and learning correlates. The link between FTP and self-determination theory is discussed.  相似文献