Blindheit und die kulturelle Produktion visuellen Sinns

By drawing on qualitative episodic interviews with blind people the study shows how practices of looking are culturally instructed and how visual culture produces social subjects. Two empirical examples are used to illustrate this. The first refers to blind people??s way of talking and their knowledge about the look of persons (in the sense of visual attractiveness) in order to show how this category is made relevant or irrelevant due to the current situation. This marks the category as a discursive instruction of how to look at people. The other example draws on blind people??s strategies of ??repairing?? situations which were unintentionally damaged by them in interactions. The analysis of those strategies shows two things: firstly how the visual perception of people is structured in interactions; secondly how the subject position ??blind?? reproduces the order of the visual culture. In the end, these strategies restore and confirm a visual order of categorizing persons in interaction. Summarised we learn that visual culture normalizes practices of seeing as well as practices of blindness and produces ??normal?? and ??deviant?? visual subjects.     

Hochkulturelle Praxis und Frame-Selektion

This paper develops an explanation of cultural consumption that is beyond structural relations and therefore brings the logic of action underlying cultural consumption into focus. In order to do so, central concepts from rational-choice-theory and practice-theory are taken into account and combined by means of the model of frame-selection (MFS). It results an integrative model which traces cultural consumption back to the interplay of opportunities, preferences, orientations, and routines, the former two being rather consciously considered parameters of a rational choice- and the latter two automatically processed cultural internalisations. Empirically the model is tested by analysing highbrow cultural consumption behaviour. It can be shown that preferences, opportunities, orientations, and routines each have an independent influence besides structural variables. Moreover, it can be observed that with cultural orientations and routines being strongly internalized the effects of preferences and opportunities decrease, which is in line with the interaction assumed by the MFS.     

Moment characterization of higher-order risk preferences

This article presents a characterization of higher-order risk preferences such as prudence or temperance in terms of statistical moments. Our results, which are generalizations of Roger (Theory Decis, 70(1):27–44, 2011) and Ekern (Econ Lett, 6(4), 329–333, 1980), give a better understanding of how higher-order risk preferences relate to skewness preference and kurtosis aversion. While they are not based on expected utility theory, an implication within that theory is that all commonly used utility functions exhibit skewness preference and kurtosis aversion.     

Retail Strategies for Extended Warranty Sales and Impact on Manufacturer Base Warranties

Consider two competing manufacturers selling their products through the same retailer. If this retailer derives profits from extended warranty sales, the manufacturers face a dilemma in setting their base warranties. Although they have incentive to increase their warranties to make their products attractive to consumers, the retailer might prefer selling lower‐warranty products to enhance extended warranties sales. We develop a stylized model to determine and analyze optimal manufacturer and retailer strategies in this setting. Consistent with the ongoing decline in warranties for products that are sold through independent retailers, we show that these interactions exert downward pressure on manufacturer warranties. Rather than pitching the extended warranty at the checkout after customers have selected a certain product, we find that retailers can often benefit from inducing simultaneous consideration of product and extended warranty characteristics, for example by posting extended warranty information right on the product shelf.     

Inventory Record Inaccuracy,Double Marginalization,and RFID Adoption

Most retailers suffer from substantial discrepancies between inventory quantities recorded in the system and stocks truly available to customers. Promising full inventory transparency, radio frequency identification (RFID) technology has often been suggested as a remedy to the problem. We consider inventory record inaccuracy in a supply chain model, where a Stackelberg manufacturer sets the wholesale price and a retailer determines how much to stock for sale to customers. We first analyze the impact of inventory record inaccuracy on optimal stocking decisions and profits. By contrasting optimal decisions in a decentralized supply chain with those in an integrated supply chain, we find that inventory record inaccuracy exacerbates the inefficiencies resulting from double marginalization in decentralized supply chains. Assuming RFID technology can eliminate the problem of inventory record inaccuracy, we determine the cost thresholds at which RFID adoption becomes profitable. We show that a decentralized supply chain benefits more from RFID technology, such that RFID adoption improves supply chain coordination.     

Migration,masculinity and social class: Insights from Pikine,Senegal

In the shattered economy of Dakar, many young men feel stuck in prolonged bachelorhood. Handed‐down role expectations can often not be met due to dire economic prospects. Drawing on fieldwork in Pikine, an urban area within the Dakar region of Senegal, between 2011 and 2013, this article reflects upon the relation between risk, migration, social class and masculinity. Through migration to unknown destinations and by enduring the many challenges and hardships associated with it, in the hope of eventually reaching a higher social class upon return, young men wish to fix and rewrite their masculine identities. To pursue this aim even the oddest job in Europe becomes acceptable. At home, however, many work opportunities are considered to be beneath their social class. Most male urbanites seek jobs that are rewarded with respect and authority, and often assemble their choices about pursuing certain income‐generating activities considering notions of class.     

Consolidated findings from 6 years research on the age-differentiated design of human-computer interaction

The fast aging of many western and eastern societies and their increasing reliance on information technology create a compelling need to reconsider older users' interactions with computers. This paper summarizes the results of 6 years of research on the age-differentiated design of human-computer interaction. The well-known model of human information processing served as the theoretical framework. The model components 'sensory processing', 'perception', 'working memory', 'decision and response selection' and 'response execution' were analyzed exemplarily in task settings on project management. In seven empirical studies with a total number of 405 participants between 20 and 77 years the human-computer interaction was analyzed regarding effectiveness, efficiency and user satisfaction. For most but not all studies the results reveal that age-induced differences in human-computer interaction can best be compensated by an ergonomic 'design for all'. In some cases however an age-specific approach is favorable.     

Empirical evaluation of the implementation of the EMA guideline on missing data in confirmatory clinical trials: Specification of mixed models for longitudinal data in study protocols

In confirmatory clinical trials, the prespecification of the primary analysis model is a universally accepted scientific principle to allow strict control of the type I error. Consequently, both the ICH E9 guideline and the European Medicines Agency (EMA) guideline on missing data in confirmatory clinical trials require that the primary analysis model is defined unambiguously. This requirement applies to mixed models for longitudinal data handling missing data implicitly. To evaluate the compliance with the EMA guideline, we evaluated the model specifications in those clinical study protocols from development phases II and III submitted between 2015 and 2018 to the Ethics Committee at Hannover Medical School under the German Medicinal Products Act, which planned to use a mixed model for longitudinal data in the confirmatory testing strategy. Overall, 39 trials from different types of sponsors and a wide range of therapeutic areas were evaluated. While nearly all protocols specify the fixed and random effects of the analysis model (95%), only 77% give the structure of the covariance matrix used for modeling the repeated measurements. Moreover, the testing method (36%), the estimation method (28%), the computation method (3%), and the fallback strategy (18%) are given by less than half the study protocols. Subgroup analyses indicate that these findings are universal and not specific to clinical trial phases or size of company. Altogether, our results show that guideline compliance is to various degrees poor and consequently, strict type I error rate control at the intended level is not guaranteed.