Strategies for Selling Paid Content on Newspaper and Magazine Web Sites: An Empirical Analysis of Bundling and Splitting of News and Magazine Articles

More and more newspaper and magazine Web sites offer paid content. However, selling information goods at a price higher than the marginal cost means finding a strategy for product or price differentiation. A possible strategy to solve this problem is the bundling of information goods. In this article, we analyze empirically, with quantitative statistic methods, strategies for selling bundled and unbundled content on newspaper and magazine Web sites. This analysis is based on the theoretical approach of Bakos and Brynjolfsson (1996). The article shows that a cannibalization takes place if the same bundle of information goods is offered in offline (printed) and online (digital) media at the same time. Traditional bundling models work nonetheless in an online media if the online content is rebundled (e.g., as dossiers about a topic), but thereby do not compete with the printed version.     

Shifting the Focus of Undergraduate Physics and Engineering Courses

Science & Education -     

Fatigue-related changes in technique emerge at different timescales during repetitive training

Training consisting of numerous repetitions performed as closely as possible to ideal techniques is common in sports and every-day tasks. Little is known about fatigue-related technique changes that emerge at different timescales when repeating complex actions such as a karate front kick. Accordingly, 15 karatekas performed 600 kicks (1 pre-block and 9 blocks). The pre-block comprised 6 kicks (3 with each leg) at maximum intensity (K-100%). Each block comprised 60 kicks (10 with each leg) at 80% of their self-perceived maximum intensity (K-80%) plus 6 K-100%. In between blocks, the participants rested for 90 seconds. Right leg kinematics (peak joint angles, peak joint angular velocities, peak joint linear resultant velocities, and time of occurrence of peaks) and kick duration corresponding to the K-80% were measured resulting in numerous variations with fatigue. At the timescale of tens of seconds, the changes involved variables that were related to velocity of execution (slowed down), while variables related to movement form were hardly affected. At the timescale of tens of minutes, the opposite results were observed. These findings challenge the long-standing rationale underlying repetitive training, suggesting instead that such involuntary variations in technique might play a crucial role in motor skill training     

Accuracy and precision of loadsol® insole force-sensors for the quantification of ground reaction force-based biomechanical running parameters

Force plates represent the “gold standard” in measuring running kinetics to predict performance or to identify the sources of running-related injuries. As these measurements are generally limited to laboratory analyses, wireless high-quality sensors for measuring in the field are needed. This work analysed the accuracy and precision of a new wireless insole forcesensor for quantifying running-related kinetic parameters. Vertical ground reaction force (GRF) was simultaneously measured with pit-mounted force plates (1?kHz) and loadsol^® sensors (100?Hz) under unshod forefoot and rearfoot running-step conditions. GRF data collections were repeated four times, each separated by 30 min treadmill running, to test influence of extended use. A repeated-measures ANOVA was used to identify differences between measurement devices. Additionally, mean bias and Bland–Altman limits of agreement (LoA) were calculated. We found a significant difference (p?® devices for these parameters. For these same parameters, the LoA analysis showed that 95% of all measurement differences between insole and force plate measurements were less than 12%, demonstrating high precision of the sensors. However, highly dynamic behaviour of GRF, such as force rate, is not yet sufficiently resolved by the insole devices, which is likely explained by the low sampling rate.     

White Paper: functionality and efficacy of wrist protectors in snowboarding—towards a harmonized international standard

The wrist is the most frequently injured body region among snowboarders. Studies have shown that the risk of sustaining a wrist injury can be reduced by wearing wrist protection. Currently, there are a wide variety of wrist protection products for snowboarding on the market that offer a range of protective features. However, there are no minimum performance standards for snowboarding wrist protectors worldwide. The International Society for Skiing Safety convened a task force to develop a White Paper to evaluate the importance and necessity of a minimum performance for all wrist protectors used in snowboarding. The White Paper outlines the need for a general framework for a harmonized international standard and reviews the existing evidence. Therefore, this White Paper may serve as a common base for future discussions. The broader goal of developing and implementing such a standard is to reduce the incidence and the severity of wrist injuries in snowboarding without increasing the risk of adverse events, such as upper arm or shoulder injury. The European standard for inline skating wrist protectors (EN 14120) can serve as a starting point for efforts related to a standard for snowboard wrist protectors, but certain modifications to the standard would be required. It is hypothesized that implementation of a snowboarding wrist protector standard would result in fewer and less severe wrist injuries in the sport and could translate into more riding days for healthy snowboarders and significant health-care costs savings.     

Offensichtlich unsichtbar Die P?dagogisierung des Umgangs mit Wissen im Kontext des lebenslangen Lernens

Der vorliegende Beitrag besch?ftigt sich unter Bezugnahme auf einen systemtheoretischen Kommunikationsbegriff mit der (p?dagogischen) Strukturierung des Lernens Erwachsener. Er geht von der These aus, dass die P?dagogisierung des lernbezogenen Umgangs mit Wissen im Erwachsenenalter unsichtbar (gemacht) wird. Auf der Grundlage eines abgeschlossenen DFG-Projekts werden unterschiedliche Formen p?dagogischer Kommunikation dargestellt und das in ihren Settings, ihrer kommunikativen Verfasstheit und den Mustern ihrer Strukturierung eingelagerte Invisibilisierungspotenzial herausgearbeitet. Vor diesem Hintergrund wird das Konzept des Lebenslangen Lernens als eine entwickelte Form des Umgangs mit dem Paradox der (Un-)Sichtbarkeit p?dagogischer Kommunikation interpretiert. Was diese Institutionalisierungsform des Lernens kennzeichnet, ist somit eine doppelt gegenl?ufige Gleichzeitigkeit von Visibilisierung und Invisibilisierung.     

Casting the die before the die is cast: the importance of the home numeracy environment for preschool children

Mathematical competencies are important not only for academic achievement at school but also for professional success later in life. Although we know a lot about the impact of “Home Literacy Environment” on the development of early linguistic competencies, research on “Home Numeracy Environment” (HNE) and the assessment of its influence on the development of mathematical abilities is in its infancy. We still lack studies analysing this relationship and simultaneously controlling for other variables concerning the individual and the environment. Thus, in this article, we focussed on the development of mathematical competencies in a sample of 609 German children from the end of kindergarten until the end of Grade 1. In particular, we were interested in the role HNE plays in regard to this development while controlling for age, sex, intelligence, rapid naming, number span, linguistic competencies, kindergarten attendance and socioeconomic status. Moreover, HNE was compared between families with or without a history of mathematical disability. HNE was not only an important predictor of mathematical abilities at the end of kindergarten, but it also influenced the further development of mathematical competencies above and beyond its initial impact. Families with a history of dyscalculia provided a more unfavourable HNE than families with no such problems. Results are shown in a structural equation model, which highlights the importance of HNE. The findings indicate that those involved in policy and intervention should focus more on the learning environments in families to improve children's achievement.