Expertise and error in diagnostic reasoning

An investigation is presented in which a computer simulation model (DIAGNOSER) is used to develop and test predictions for behavior of subjects in a task of medical diagnosis. The first experiment employed a process-tracing methodology in order to compare hypothesis generation and evaluation behavior of DIAGNOSER with individuals at different levels of expertise (students, trainees, experts). A second experiment performed with only DIAGNOSER identified conditions under which errors in reasoning in the first experiment could be related to interpretation of specific data items. Predictions derived from DIAGNOSER's performance were tested in a third experiment with a new sample of subjects. Data from the three experiments indicated that (1) form of diagnostic reasoning was similar for all subjects trained in medicine and for the simulation model, (2) substance of diagnostic reasoning employed by the simulation model was parable with that of the more expert subjects, and (3) errors in subjects' reasoning were attributable to deficiencies in disease knowledge and the interpretation of specific patient data cues predicted by the simulation model.     

Response–reinforcer dependency and resistance to change

The effects of the response–reinforcer dependency on resistance to change were studied in three experiments with rats. In Experiment 1, lever pressing produced reinforcers at similar rates after variable interreinforcer intervals in each component of a two‐component multiple schedule. Across conditions, in the fixed component, all reinforcers were response‐dependent; in the alternative component, the percentage of response‐dependent reinforcers was 100, 50 (i.e., 50% response‐dependent and 50% response‐independent) or 10% (i.e., 10% response‐dependent and 90% response‐independent). Resistance to extinction was greater in the alternative than in the fixed component when the dependency in the former was 10%, but was similar between components when this dependency was 100 or 50%. In Experiment 2, a three‐component multiple schedule was used. The dependency was 100% in one component and 10% in the other two. The 10% components differed on how reinforcers were programmed. In one component, as in Experiment 1, a reinforcer had to be collected before the scheduling of other response‐dependent or independent reinforcers. In the other component, response‐dependent and ‐independent reinforcers were programmed by superimposing a variable‐time schedule on an independent variable‐interval schedule. Regardless of the procedure used to program the dependency, resistance to extinction was greater in the 10% components than in the 100% component. These results were replicated in Experiment 3 in which, instead of extinction, VT schedules replaced the baseline schedules in each multiple‐schedule component during the test. We argue that the relative change in dependency from Baseline to Test, which is greater when baseline dependencies are high rather than low, could account for the differential resistance to change in the present experiments. The inconsistencies in results across the present and previous experiments suggest that the effects of dependency on resistance to change are not well understood. Additional systematic analyses are important to further understand the effects of the response–reinforcer relation on resistance to change and to the development of a more comprehensive theory of behavioral persistence.     

Perfectionism in Argentina and the United States: Measurement Structure,Invariance, and Implications for Depression

The Revised Almost Perfect Scale (APS–R; Slaney, Mobley, Trippi, Ashby, &; Johnson, 1996 Slaney, R. B., Mobley, M., Trippi, J., Ashby, J. S., &; Johnson, D. (1996). Almost Perfect Scale Revised. Psyctests. doi:10.1037/t02161-000[Crossref] , [Google Scholar]) was designed to measure perfectionistic strivings (standards), perfectionistic concerns (discrepancy), and preferences for neatness and organization (order). In this study, English and Spanish (Arana, Keegan, &; Rutsztein, 2009 Arana, F. G., Keegan, E. G., &; Rutsztein, G. (2009). Adaptación de una medida multidimensional de perfeccionismo: la Almost Perfect Scale–Revised (APS–R). Un estudio preliminar sobre sus propiedades psicométricas en una muestra de estudiantes universitarios argentinos [Adaptation of a measure of multidimensional perfectionism: The Almost Perfect Scale–Revised. A preliminary study about its psychometrical properties on a sample of Argentine university students]. Evaluar, 9, 35–53. [Google Scholar]) versions of the APS–R were compared in samples of 283 college students in Argentina and 311 U.S. students. The results offered support for cross-national scalar invariance for discrepancy and order items but standards items, with a few exceptions, raised concerns about their cross-national comparability. Tests of latent means revealed no differences between the countries for discrepancy, but the order factor mean was higher in the U.S. sample. Age and gender had negligible effects on measurement models. Discrepancy was strongly related to depressive symptoms for both samples. Unlike in the U.S. sample, there was a significant association for the Argentina sample between standards and discrepancy. Overall, results indicated that discrepancy items performed well, order items were adequate with some measurement adjustments, and standards items should be revisited for their cross-cultural utility. Translation issues and general values in Argentina and the United States (e.g., collectivism–individualism) are discussed that might affect how perfectionism is understood and measured in different cultural contexts.