Umgang mit Jugenddelinquenz

For the German Juvenile Delinquency Court Association (Deutsche Vereinigung für Jugendgerichte und Jugendgerichtshilfen e.V.), which comprises researchers and practitioners in the field alike, the Lower Saxony Crime Research Institute (Kriminologisches Forschungsinstitut Niedersachsen e.V.), one of the most important institutions in Germany, in 1998 has compiled a detailed study ?Exclusion, Violence and Delinquency in the Life of young people — children and adolescents as victims and perpetrators“, comprising an extensive review of the literature with extensive own research results. The study takes a politically clear position: juvenile delinquency declines in quantity and intensity. Contradictory findings are based on statistical bias. Consequently, the policy of decriminalization — putting educational before correctional measures — has to be vigorously continued. The study displays a wealth of statistical material — and a wealth of serious, sometimes unforgivable methodological mistakes. At several occasions the authors explicitly dump unwanted findings. The considerable discrepancies between the main text body and the executive summary for the hurried reader further undermines confidence in the professionalism of the authors.     

Modern Myths

This article outlines some basic characteristics of modern myths that fundamentally differ from the traditional myths on which most myth research is based, namely: their relation to time, and their relation to themselves. The article also takes a closer look at the implications these differences have for our present state of Being. The aim is not to offer yet another variation on the academic discussion of myths, but rather to provide a starting point for further discussion about the peculiarities and impacts pertaining to modern myths.     

Bayesian adaptive dose‐escalation designs for simultaneously estimating the optimal and maximum safe dose based on safety and efficacy

The main purpose of dose‐escalation trials is to identify the dose(s) that is/are safe and efficacious for further investigations in later studies. In this paper, we introduce dose‐escalation designs that incorporate both the dose‐limiting events and dose‐limiting toxicities (DLTs) and indicative responses of efficacy into the procedure. A flexible nonparametric model is used for modelling the continuous efficacy responses while a logistic model is used for the binary DLTs. Escalation decisions are based on the combination of the probabilities of DLTs and expected efficacy through a gain function. On the basis of this setup, we then introduce 2 types of Bayesian adaptive dose‐escalation strategies. The first type of procedures, called “single objective,” aims to identify and recommend a single dose, either the maximum tolerated dose, the highest dose that is considered as safe, or the optimal dose, a safe dose that gives optimum benefit risk. The second type, called “dual objective,” aims to jointly estimate both the maximum tolerated dose and the optimal dose accurately. The recommended doses obtained under these dose‐escalation procedures provide information about the safety and efficacy profile of the novel drug to facilitate later studies. We evaluate different strategies via simulations based on an example constructed from a real trial on patients with type 2 diabetes, and the use of stopping rules is assessed. We find that the nonparametric model estimates the efficacy responses well for different underlying true shapes. The dual‐objective designs give better results in terms of identifying the 2 real target doses compared to the single‐objective designs.     

Should I Stay or Should I Go? Explaining Turnover Intentions with Organizational Identification and Job Satisfaction*

The social identity approach is a powerful theoretical framework for the understanding of individuals' behaviour. The main argument is that individuals think and act on behalf of the group they belong to because this group membership adds to their social identity, which partly determines one's self‐esteem. In the organizational world, social identity and self‐categorization theories state that a strong organizational identification is associated with low turnover intentions. Because identification is the more general perception of shared fate between employee and organization, we propose that the relationship between identification and turnover will be mediated by job satisfaction as the more specific evaluation of one's task and working conditions. In four samples we found organizational identification feeding into job satisfaction, which in turn predicts turnover intentions.     

The Value of Weather Information for E‐Commerce Operations

To be efficient, logistics operations in e‐commerce require warehousing and transportation resources to be aligned with sales. Customer orders must be fulfilled with short lead times to ensure high customer satisfaction, and the costly under‐utilization of workers must be avoided. To approach this ideal, forecasting order quantities with high accuracy is essential. Many drivers of online sales, including seasonality, special promotions and public holidays, are well known, and they have been frequently incorporated into forecasting approaches. However, the impact of weather on e‐commerce operations has not been rigorously analyzed. In this study, we integrate weather data into the sales forecasting of the largest European online fashion retailer. We find that sunshine, temperature, and rain have a significant impact on daily sales, particularly in the summer, on weekends, and on days with extreme weather. Using weather forecasts, we have significantly improved sales forecast accuracy. We find that including weather data in the sales forecast model can lead to fewer sales forecast errors, reducing them by, on average, 8.6% to 12.2% and up to 50.6% on summer weekends. In turn, the improvement in sales forecast accuracy has a measurable impact on logistics and warehousing operations. We quantify the value of incorporating weather forecasts in the planning process for the order fulfillment center workforce and show how their incorporation can be leveraged to reduce costs and increase performance. With a perfect information planning scenario, excess costs can be reduced by 11.6% compared with the cost reduction attainable with a baseline model that ignores weather information in workforce planning.     

Drittmittel als Performanzindikator der Wissenschaftlichen Forschung

Resources within and between higher education and research institutions are increasingly allocated according to scientific performance. Evaluation exercises and the measurement of research performance take on a new role in this context. Third party research income is a performance indicator which is rather easy to measure and is used in most of the new performance-based evaluation procedures. This paper sets out to scrutinize the meaning and validity of third party research income. We studied research teams from three different research fields with a mixed quantitative / qualitative approach. The focus is on the causal relations between institutional / input indicators, third party research income as another input indicator, and a variety of output indicators of scientific production. An important result is that third party money has a positive effect on performance only below a certain and discipline-specific threshold. Further analysis shows that output performance is to a great extent field-specific. The context conditions for scientific production differ greatly, so that comparative performance assessments are only valid within homogeneous research fields. Another important result is that output performance is multidimensional and cannot be measured by bibliometric indicators only. These findings have implications for the rationality of the evaluation assessment exercises as well as for the funding decisions of science foundations, ministries of science and — increasingly, the heads of universities and departments. These topics are discussed in the last chapter as well as the implications for further research.     

Integration of Stochastic Effects and Data Uncertainties into the Design of Process Equipment

Stochastic effects and data uncertainties are present in any engineering calculation. Their impact may be particularly important if they concern the design of process equipment. A calculation model for the dynamic behavior of a heat exchanger and procedures to deal with the related uncertainties are presented. Their propagation through the calculation by means of a Monte Carlo approach is shown. The temperature at the heat exchanger outlet and the step response of a sudden variation in the heat exchanger inlet temperature are simulated and evaluated by way of example. It is demonstrated that the inclusion of stochastic effects and uncertainties provides a more reliable basis for design decisions and hence reduces the probability of errors.     

What is Loss Aversion?

A behavioral definition of loss aversion is proposed and its implications for original and cumulative prospect theory are analyzed. Original prospect theory is in agreement with the new loss aversion condition, and there utility is capturing all effects of loss aversion. In cumulative prospect theory loss aversion is captured by both the weighting functions and the utility function. Further, some restrictions apply for the weighting functions involved in the latter model.We are indebted to Michèle Cohen and Peter Wakker for helpful comments. The suggestions of an anonymous referee have improved the presentation of the paper.     

The Development of Students' Mathematics Self‐Concept in Relation to Gender: Different Countries,Different Trajectories?

Gender differences in the development of children's and adolescents' academic self‐perceptions have received increasing attention in recent years. This study extends previous research by examining the development of mathematics self‐concept across grades 7–12 in three cultural settings: Australia (Sydney; N=1,333), the United States (Michigan; N=2,443), and Germany (four federal states; N=4,688). Results of latent growth curve models document very similar patterns of self‐concept development in males and females in the three settings. First, gender differences in favor of boys were observed at the beginning of the observation period (grade 7). Second, gender was not significantly related to self‐concept change in either group, meaning that initial differences persisted across time. Third, the results provided no evidence that the form of the longitudinal change trajectories for mathematics self‐concept differed across the cultural settings. This pattern of results is inconsistent with explanatory models that predict converging or diverging gender differences in mathematics self‐concept. Furthermore, the results indicate that self‐concept development may be highly similar across western cultural settings.