8 research outputs found
Scoring method of a Situational Judgment Test:influence on internal consistency reliability, adverse impact and correlation with personality?
textabstractSituational Judgment Tests (SJTs) are increasingly used for medical school selection. Scoring an SJT is more complicated than scoring a knowledge test, because there are no objectively correct answers. The scoring method of an SJT may influence the construct and concurrent validity and the adverse impact with respect to non-traditional students. Previous research has compared only a small number of scoring methods and has not studied the effect of scoring method on internal consistency reliability. This study compared 28 different scoring methods for a rating SJT on internal consistency reliability, adverse impact and correlation with personality. The scoring methods varied on four aspects: the way of controlling for systematic error, and the type of reference group, distance and central tendency statistic. All scoring methods were applied to a previously validated integrity-based SJT, administered to 931 medical school applicants. Internal consistency reliability varied between .33 and .73, which is likely explained by the dependence of coefficient alpha on the total score variance. All scoring methods led to significantly higher scores for the ethnic majority than for the non-Western minorities, with effect sizes ranging from 0.48 to 0.66. Eighteen scoring methods showed a significant small positive correlation with agreeableness. Four scoring methods showed a significant small positive correlation with conscientiousness. The way of controlling for systematic error was the most influential scoring method aspect. These results suggest that the increased use of SJTs for selection into medical school must be accompanied by a thorough examination of the scoring method to be used
Hydrogen generation by hydrolysis reaction using magnesium alloys with long period stacking ordered structure
n the present work are reported the hydrogen generation performances of Long Period Stacking Ordered (LPSO) compounds with 18R, 14H and 10H-type structures by hydrolysis reaction in simulated seawater solution (35 g/L NaCl). LPSO compounds and LPSO + Mg alloys synthesized by induction melting are described in the light of their microstructural and electrochemical properties. Except for 10H type, all LPSO present improved H2 generation features compared to pure Mg. Indeed, 80% of the reaction is achieved in less than 40 minutes. The highest generation yield of 90% is obtained for single phase LPSO Mg87.6Ni5.5Y6.9. Alloys containing both Mg and LPSO beneficiate from galvanic coupling between the two phases leading to higher reactivity. The activation energies of 27.3 and 85.4 kJ/mol determined for Mg91Ni4Y5 (14H + Mg) and Mg83.3Cu7.2Y9.5 (18R) respectively clearly highlight this benefit from galvanic coupling
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Viscosity Effects on Blood Flow Dynamics: Influence of Isovolemic Hemodilution on Focal Cerebral Ischemia
In recent years there has been considerable clinical interest in the efficacy of both hypervolemic hemodilution [6, 7, 20] and isovolemic hemodilution [9, 26] in the prevention or treatment of cerebral ischemia. There has also been considerable experimental work in this area, particularly with hypervolemic hemodilution [24, 25]. A consistent problem encountered in the experimental work, however, has been the fact that hypervolemia increases intracranial pressure [25] and results in cardiac overloading. This limits the applicability of hypervolemic hemodilution, particularly in patients with increased intracranial pressure and in elderly stroke patients who frequently have limited cardiac reserve