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.     

Firm size and board diversity

This study seeks to understand the relation between firm size and supervisory board composition. Specifically, we ask if and how firm size influences occupational and international background diversity in supervisory boards. Relying on resource dependence theory and theories of organizational behavior, we hypothesize that board diversity with respect to directors’ occupational background will increase with firm size, while the relation between firm size and board diversity with respect to directors’ international background will be concave. Using archival data for supervisory board members of 151 German firms listed in the German stock exchange indices DAX, MDAX, SDAX and TecDAX for the business year 2005, we find empirical support for our hypotheses: Both, occupational and international background diversity increase with increasing firm size, but international background diversity does so at decreasing rates.     

Bivariate pointing movements on large touch screens: investigating the validity of a refined Fitts' Law

On the basis of three empirical studies Fitts' Law was refined for bivariate pointing tasks on large touch screens. In the first study different target width parameters were investigated. The second study considered the effect of the motion angle. Based on the results of the two studies a refined model for movement time in human-computer interaction was formulated. A third study, which is described here in detail, concerns the validation of the refined model. For the validation study 20 subjects had to execute a bivariate pointing task on a large touch screen. In the experimental task 250 rectangular target objects were displayed at a randomly chosen position on the screen covering a broad range of ID values (ID= [1.01; 4.88]). Compared to existing refinements of Fitts' Law, the new model shows highest predictive validity. A promising field of application of the model is the ergonomic design and evaluation of project management software. By using the refined model, software designers can calculate a priori the appropriate angular position and the size of buttons, menus or icons.     

Can’t buy me laughter – Humour in organisational change

This article reflects upon the potential role of humour during an organisational change process. We focus on three facets that are of special importance during change: coping with the change, resisting the change, and leading the change. For each facet, we present relevant quantitative and qualitative studies; and in a final section, we derive implications for employees, leaders, and organisations.In regards to coping with change, we focus on the stress-buffering effects of humour. High-humour individuals maintain higher levels of positive affect in stressful situations and appraise a potentially stressful event as a positive challenge rather than a threat. In regards to resisting change, we show that aggressive humour can be an indicator of serious distress and a means to express resistance towards authority or aspects of the change process. In regards to leading change, we point out how effective leaders may utilise humour to manage followers’ emotions in order to increase positive affect and to reduce perceived threat associated with change.We conclude by suggesting how humour can be used as a diagnostic tool, to foster a humour-supportive climate, to improve communication strategies, and to support an error management culture.     

Effects of Three Caregiver Interventions: Support,Educational Literature,and Creative Movement

The primary focus of this study is to compare the effectiveness of three distinct intervention techniques in relieving some of the stress experienced by midlife daughters' caregiving for their frail mothers. The three techniques are: (a) a home-based literature “tip of the week” group, (b) a caregiver's support group, and (c) a creative-movement group. Based on a review of caregiving literature, no other studies have utilized a home-based literature intervention or a creative-movement intervention with midlife daughters providing informal care to frail mothers. As part of the weekly assessment evaluation, participants were asked to rate how helpful the previous week's session was with respect to five mental health variables: irritability, depression, anxiety, stress, and concentration. Overall, the support-based group had higher average scores for each of the five mental health variables and the highest overall mental health score. Future research and promising applications of future intervention programs are discussed.     

Multiscale change point detection for dependent data

In this article we study the theoretical properties of the simultaneous multiscale change point estimator (SMUCE) in piecewise-constant signal models with dependent error processes. Empirical studies suggest that in this case the change point estimate is inconsistent, but it is not known if alternatives suggested in the literature for correlated data are consistent. We propose a modification of SMUCE scaling the basic statistic by the long run variance of the error process, which is estimated by a difference-type variance estimator calculated from local means from different blocks. For this modification we prove model consistency for physical-dependent error processes and illustrate the finite sample performance by means of a simulation study.     

Living long-term with HIV/AIDS: exploring impact in psychosocial and vocational domains

In the last decade, new treatments for the Human Immunodeficiency Virus (HIV) and Acquired Immune Deficiency Syndrome (AIDS) have led to improved health and longer life expectancies for many HIV-positive individuals. Coping with HIV/AIDS as a chronic, rather than terminal illness presents new challenges for those living with the disease and for service providers. This review of HIV/AIDS-related literature attempts to address the major medical, psychological and psychosocial challenges related to living long-term with HIV/AIDS and consider how they may present obstacles to attainment of educational and vocational goals for HIV-positive individuals. Implications for service providers and suggestions for future research are discussed. An exploratory study of needs assessment is proposed.