Mathematics for teaching: A form of applied mathematics

In this article we elaborate a conceptualisation of mathematics for teaching as a form of applied mathematics (using Bass's idea of characterising mathematics education as a form of applied mathematics) and we examine implications of this conceptualisation for the mathematical preparation of teachers. Specifically, we focus on issues of design and implementation of a special kind of mathematics tasks whose use in mathematics teacher education can support the development of knowledge of mathematics for teaching. Also, we discuss broader implications of the article for mathematics teacher education, including implications for mathematics teacher educators' knowledge for promoting mathematics for teaching.     

Intercultural learning in English as foreign language instruction: The importance of teachers’ intercultural experience and the usefulness of precise instructional directives

The development of intercultural competence, especially in foreign language instruction, is considered a key goal of teaching in German schools. The present article sheds light on the teaching of intercultural topics in the context of English as a foreign language (EFL). It presents the results of an analysis of data from a larger study (DESI study – Assessment of Student Achievements in German and English as a Foreign Language) bringing the intercultural experience of teachers and observable aspects of instruction into focus. Videotapes of EFL-classroom instruction of 9th and 10th grade students are analyzed in order to assess characteristic of the implementation of intercultural topics. The study reveals the impact of teachers’ intercultural experience on the quality of their intercultural instruction. Furthermore, the results indicate that precise external directives for particular lessons can help teachers put intercultural topics into practice.     

Exploiting Hierarchy in Text Categorization

With the recent dramatic increase in electronic access to documents, text categorization—the task of assigning topics to a given document—has moved to the center of the information sciences and knowledge management. This article uses the structure that is present in the semantic space of topics in order to improve performance in text categorization: according to their meaning, topics can be grouped together into meta-topics, e.g., gold, silver, and copper are all metals. The proposed architecture matches the hierarchical structure of the topic space, as opposed to a flat model that ignores the structure. It accommodates both single and multiple topic assignments for each document. Its probabilistic interpretation allows its predictions to be combined in a principled way with information from other sources. The first level of the architecture predicts the probabilities of the meta-topic groups. This allows the individual models for each topic on the second level to focus on finer discriminations within the group. Evaluating the performance of a two-level implementation on the Reuters-22173 testbed of newswire articles shows the most significant improvement for rare classes.     

Correlates of health in adolescent elite athletes and adolescents: A cross-sectional study of 1016 adolescents

The primary aim of this cross-sectional study was to compare subjective correlates of health, such as nutrition, self-esteem, sleep and stress, between adolescent elite athletes (n?=?625) and a reference group of adolescents (n?=?391) not involved in elite sports. A secondary aim was to study predictors for self-perceived stress. A questionnaire was e-mailed to all participants containing valid questions about competence-based self-esteem, nutrition, self-perceived stress and sleep. Our results show that adolescent elite athletes reported significantly (p?p?相似文献   

Combinations of Epoch Durations and Cut-Points to Estimate Sedentary Time and Physical Activity Among Adolescents

The purpose of the current study was to investigate how combinations of different epoch durations and cut-points affect the estimations of sedentary time and physical activity in adolescents. Accelerometer data from 101 adolescents were derived and 30 combinations were used to estimate sedentary time, light, moderate, vigorous, and combined moderate-to-vigorous physical activity. Data were analyzed with repeated measurement analyses of variance. Large differences of sedentary time and times of different physical activity intensities were observed between 1 s and longer epoch durations using virtually all cut-points. Generally, sedentary time, moderate physical activity, vigorous physical activity, and combined moderate-to-vigorous physical activity progressively decreased, whereas light physical activity increased with longer epoch durations. The extreme differences between cut-points were large and increased with longer epoch durations for sedentary time and for all physical activity intensities except for vigorous physical activity per epoch duration. Caution is required when cross-comparing studies using different epoch durations and cut-points. To accurately register adolescents’ spontaneous intermittent physical activity behavior, short epoch durations are recommended.     

Interacting with People who have Severe Communication Problems: Ethical considerations

People who have severe speech and communication problems have difficulties making themselves heard both in everyday communications and society at large. In spite of the positive results which have followed the development of non-vocal intervention strategies, this group of people is at risk for being left out of the social common and being alienated. It is important to realise that one cannot do in the technical what one cannot do in the ethical. Unless both social interaction and intervention with people who have severe communication impairments are based on ethical reflection, the moral standards that are applied to this group may be lower than for other people. True communicative interaction depends on the acceptance that the other partner has something of value to communicate, even if the means for expressive communication are limited and the messages are vague and difficult to understand. A moral requirement for autonomy, that is, an equal footing or right to expression, places an ethical imperative on the more competent communication partner to strive to overcome the asymmetrical relationship and help the disabled person create authentic messages. Ethics is awareness based on the reflection on moral phenomena, grounded in the norms and values of the society and typically the result of discourse and co-constructive reflection, in the form of everyday discussions as well as of public philosophical scrutiny. Communication is a vehicle of reflection and discourse may be regarded as joined reflection. Thus, time for discourse in professional work may be a prerequisite for ethical practice.