Optimizing the efficiency: adverse impact trade-off in personnel classification decisions

Different subgroups display different means on specific performance predictors, leading to the quality- diversity dilemma in the personnel selection context. However, since classification situations still arise in practice, the reality of effect sizes will lead to adverse impact in these personnel decision situations as well. The current method to estimate the classification efficiency given a set of predictors, different subgroups and their characteristics, was extended to yield the adverse impact ratio as well. Additionally, this method was implemented in an algorithm that leads to predictor weights that result in optimal trade-offs between efficiency and diversity

AKI patients have worse long-term outcomes, especially in the immediate post-ICU period

Acute kidney injury (AKI) is associated with worse outcome in the acute phase of acute illness but also in the chronic phase. In a large Danish study in this issue of Critical Care, 1-year mortality was higher in patients with AKI than in patients without AKI. Mortality was most important during the first 50 days after admission to the intensive c are unit (ICU), whereas after 2 months the survival curves of patients with AKI and those of patients without AKI were similar. The reasons for this observation are not clear, but protracted critical illness and fragility after acute critical illness probably play important roles. Because we see more and more of these patients, they should be the focus of ICU research. Consequently, ICU and post-ICU care for these patients requires focus and a more integrated approach to the specific problems of these survivors of acute critical illness

Efficiency and adverse impact of general classification decisions

Classification decisions relate to situations in which a battery of predictors is used to assign individuals to a number of different trajectories. De Corte (2000) proposed a method to estimate the classification efficiency in case the assignment of individuals to trajectories is based on least square criterion estimates. The current paper extends this method to the case where the applicants come from several subpopulations and estimates are no longer only regression weighted. The extension is motivated by the fact that using other than regression based criterion estimates for assigning applicants to the different trajectories may result in classification decisions that show substantially less adverse impact as compared to classifications in which regression based criterion estimates govern the allocation process (De Corte, Lievens & Sackett, 2007). An application of the new analytic method indicates that while classifications based on regression weighted criterion estimates lead to optimal classification efficiency, they also yield substantial adverse impact because many of the most valid predictors, and cognitive ability predictors in particular, show large effect sizes in favor of the so-called majority applicants. Alternatively, general (non regression based) classification decisions lead to a wide range of possible trade-offs between efficiency and diversity where concessions in terms of classification efficiency are compensated by more advantageous levels of adverse impact. The proposed method may be used by practitioners to alleviate the quandary between efficiency and adverse impact in a classification context

Fatigue crack behaviour : comparing three-point bend test and wedge splitting test data on vibrated concrete using Paris' law

The fatigue behaviour of concrete has become more important for the design of constructions due to the desire to build slimmer structures, which are more sensitive to fatigue loading. This article aims to evaluate and compare the fatigue crack propagation rate in vibrated concrete for four different stress ratios using the Paris-Erdogan law. The data evaluation in this article is based on crack mouth opening displacement (CMOD) measurements from cyclic three-point bending tests on single edge notched beams and from wedge splitting tests on notched cubes, obtained from experiments at Ghent University. For this study, finite element analysis is used to obtain a mathematical relationship between the CMOD and the relative crack length a/W, as well as a relationship between the stress intensity ratio ∆K and a/W. The obtained mathematical relationships were then combined with the measured CMOD values to correlate the test data to the Paris-Erdogan law. Herein, the crack propagation rate da/dN is plotted against the corresponding stress intensity range ∆K in a log-log graph. In a final step, the Paris-Erdogan law parameters C and m were obtained through linear curve fitting on the data points from the obtained graphs. The parameters C and m are then used to compare and evaluate the fatigue crack behavior in vibrated concrete, and the differences between the results from the three-point bend tests and wedge splitting tests