Adaptive progressive download based on the MPEG-4 file format

In this paper we describe how progressive download and adaptive streaming can be combined into a simple and efficient streaming framework. Based on the MPEG-4 file format (MP4) we use HTTP for transport and argue that these two components are sufficient for specifying an open streaming architecture. The client selects appropriate chunks from the MP4 file to be transferred based on (1) the header information (i.e. the “moov” box) in the first part of the file and (2) his observation of network throughput. The framework is completely client driven which allows for better server scalability and reduces signalling overhead. We discuss architecture and implementation issues such as complexity, interoperability and scalability and compare to 3GPP PSS Rel-6 adaptive streaming when appropriate. Measurements from a simple MP4/HTTP streaming client are presented showing that appropriate chunks are selected such that increased reliability is achieved.     

WHEN IS A SCHOOL ENVIRONMENT PERCEIVED AS SUPPORTIVE BY BEGINNING MATHEMATICS TEACHERS? EFFECTS OF LEADERSHIP, TRUST, AUTONOMY AND APPRAISAL ON TEACHING QUALITY

This study examines the hypothesis that the more support beginning mathematics teachers perceive and the better they evaluate the management of their school, the higher their teaching quality is. Indicators of teaching quality were how the teachers, who were in their third year in the profession, regarded themselves able to cope with the challenges of mathematics instruction and generic tasks like classroom management and how satisfied they were with their job. Indicators of support were the level of appraisal and autonomy the teachers reported. School management indicators were the administrative leadership of the principal and the climate of trust as perceived by the teachers. Our results reveal that teacher support plays an important role in the quality of beginning mathematics teachers. All quality indicators improved significantly if beginning teachers reported more appraisal and autonomy. A climate of trust plays an important role for the extent of autonomy perceived. Administrative leadership was significantly related to the amount of appraisal the teachers reported. Our results provide important information on how to steer a school so that the quality of beginning mathematics teachers is maximized.     

Studieren an der Berufsakademie oder an der Universität, Fachhochschule oder Pädagogischen Hochschule?

Beim übergang von der Schule auf die Universit?t müssen sich Abiturienten u.a. für einen bestimmten Hochschultypus entscheiden. Der Fokus in diesem Beitrag liegt auf der sogenannten Berufsakademie, die in einigen Bundesl?ndern eine interessante, aber wenig beachtete Alternative zu Universit?t, Fachhochschule und P?dagogischer Hochschule darstellt. Anhand einer gro?en L?ngsschnittstudie, die in Baden-Württemberg durchgeführt wird, werden der Leistungsstand, der famili?re Hintergrund, die beruflichen Interessen und die Studienwahlmotive von (künftigen) Studierenden an den verschiedenen Hochschultypen untersucht. Berufsakademien erwiesen sich insbesondere für Abiturienten mit weniger günstigem famili?ren Hintergrund und dem Wunsch, rasch finanziell unabh?ngig zu sein, sowie für Absolventen beruflicher Gymnasien als attraktive Alternative zur Universit?t. Berücksichtigt man die schulische Herkunft (berufliches vs. allgemeinbildendes Gymnasium), so fanden sich ?hnliche kognitive Eingangsvoraussetzungen bei Studierenden wirtschaftswissenschaftlicher F?cher an Berufsakademie, Fachhochschule und Universit?t.     

Teaching Foreign Languages at a distance

This paper is about how to teach a foreign language at a distance, i.e. how to support the learning of a foreign language by students who are not taught by teachers face‐to‐face. Much experience about this has been collected by correspondence schools and similar organisations. Among the public bodies of importance here should be mentioned the state‐owned and state‐run French Centre National d'Enseignement par Correspondence and Athabasca University in Alberta, Canada. Little seems to have been published about teaching and learning foreign languages at a distance, although Rousseau 1977 and contributions to ICDE and EHSC conferences (in 1982 and 1979) have surveyed essential problem areas. Experiences of teaching English as a foreign language provide the basis from which many considerations are examined.     

Early stages in building hybrid activity between school and work: the case of PénArt

This formative intervention documents the emergence of a hybrid activity aiming at student engagement and academic achievement. In this context-bound study, early stages of this activity consisted in establishing PénArt meant to enable high school students with difficulties to start up their own business at school. It involved reaching agreements between a high school and a youth centre so that high school students engage in the production and selling of their branded t-shirt. At the frontiers of their respective activity system, students, youth workers, special education teachers and members of the school board took actions to cross boundaries and redefine their interrelations. Cultural historical activity theory was fruitful to document the development of a new object-oriented activity. Tensions and contradictions revelaled to be the key moments in the emergence of the hybrid activity. Expansive learning led us to understand that, in a conflicting situation, a collective’s agentive actions create an expansive form of learning and leads to a successful entrepreneurship experience. Change laboratory capacity to foster change for cooperative education in Quebec was successful. The students enrolled in a regional entrepreneurship contest and won it. That was a significant event for students with low self-esteem linked with their performance at school.     

What factors motivate male and female Generation Z students to become engaged as peer teachers? A mixed-method study among medical and dental students in the gross anatomy course

Peer-teaching is widely established in anatomy teaching and offers well-described advantages. Nevertheless, at Ulm University, Germany, a reduction in the number of peer teacher applicants for the dissection course was observed. This study examined factors related to the attractiveness of a position as a peer teacher for Generation Z students. Participants of the gross anatomy course were asked to evaluate factors influencing the attractiveness of a peer teacher position using a six-point Likert scale. Additionally, open-ended questions were analyzed qualitatively. Sex-specific subgroup analysis was performed comparing students of low and high motivation to apply for a tutorship. Of the 374 students who participated in this study (response rate 53%), 38% stated that they were intending to apply as peer teachers. Data indicated that students displayed intrinsic motivation to apply for a tutorship because of the opportunity to improve their anatomy knowledge and/or their pleasure in teaching. In contrast, extrinsic factors like remuneration of the tutorship and its relevance for their curriculum vitae were least important. Anatomy educators underestimated the demotivating factor of the workload associated with the tutorship and encouraged students less frequently to apply than peer teachers. Only minor sex-specific differences could be identified. Nevertheless, female students were encouraged less frequently to apply than their male peers. In summary, Generation Z students apply as peer teachers because they are enthusiastic about the task. To motivate students to commit to extracurricular activities like a tutorship, anatomy educators should actively encourage students—particularly females—more frequently to apply.     

A framework for assessing market entry opportunities for internet‐based TV

Abstract

The advent of the Internet alleviates the access bottleneck to TV distribution channels and softens licensing requirements. This lowers entry barriers to TV markets via the Internet in various forms. This paper takes the German TV sector as an example to analyse the attractiveness of TV markets for new entrants. A sequential framework for entering TV markets is introduced. The skills set of an Internet‐based TV provider for such an entry is examined. Technical feasibility, legal aspects, and potential sources of revenue are considered.

Potential above average profits due to the market's oligopolistic structure, as well as an increased contestability thanks to lower market entry barriers seem to render the German TV market attractive for new entrants. In early 2002, Internet‐based TV still faced severe technical and legal constraints. The analysis suggests that once these constraints have been overcome, the Internet could be an attractive additional distribution channel for some types of television content. While existing revenue sources from the TV sector are expected to be transferable to a certain degree, the value of innovative revenue sources based on online sales cannot yet be determined. This value will depend on the future acceptance of interactivity by the viewer (e. g. Owen 1999).