Methodology for the comparison of clinical with actuarial predictions.

Techniques for the quantitative comparison of actuarial predictions (AP) as contrasted with clinical predictions (CP) are examined. The problems of validity analysis and differential validity analysis for both AP and CP along with reliability analysis of CP are considered in turn. Original data are applied to the several statistical techniques presented for assessing the foregoing issues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparison of current measures of the accuracy of feeling-of-knowing predictions.

Discusses 8 quantitative measures of feeling-of-knowing accuracy that have been used in the literature. The 3 measures considered at length are J. T. Hart's (see record 1965-13971-001) difference score, L. A. Goodman and W. H. Kruskal's (1954) gamma correlation, and the phi correlation. Quantitative relations between these measures are reported, as are connections with some basic axioms and a probabilistic conception of feeling-of-knowing accuracy. The currently most popular measure, the Hart difference score, has serious shortcomings. The Goodman-Kruskal gamma seems to be best. The remaining measures are inappropriate for the available feeling-of-knowing data for a variety of reasons. Also discussed are the implications of these results for other situations in which ordered 2?×?2 tables are examined to determine the relationship between predictions and criterion performance. (60 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predicting outcomes of psychotherapy: A comparison of predictions from two attitude theories.

Compared social judgment and dissonance theory in their ability to predict the outcomes of psychotherapy on the basis of patient-therapist attitudinal similarity. 65 mental health clinic outpatients of 16 therapists were given attitude questionnaires before and after approximately 12 therapy contacts. It was found that dissonance theory was better able than social judgment theory to predict both those attitude changes that took place and the amount of similarity that a patient perceived between himself and his therapist. On the other hand, certain concepts from social judgment theory did prove efficacious in predicting certain kinds of outcomes among certain therapy conditions, but not in the manner predicted. Finally, certain outcomes of psychotherapy were found to be unpredictable from either theory studied. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A mathematical model for the dynamic behavior of melts subjected to electromagnetic forces: Part I. model development and comparison of predictions with published experimental results

A mathematical model was developed to predict electromagnetically driven flow and (particularly) free surface behavior in melts subject to electromagnetic forces. Such melts appear in electromagnetic casters, induction furnaces, and other metal processing units. The calculations started with Maxwell’s equations and Ohm’s law, which were solved by a novel “modified hybrid technique.” The instantaneous continuity and Navier-Stokes equations (rather than their time-averaged versions) were then solved with electromagrretic forces as input. The calculations allowed for the dynamic behavior of the free surface of the melt, and electromagnetic fields were recomputed as the free surface changed. In this first part of a two-part article, the model predictions are compared with the experimental measurements of induced current, magnetic field, melt velocity, and free surface deformation reported by others.     

Molecular-dynamics study of mechanical deformation in nano-crystalline aluminum

We report on molecular-dynamics (MD) simulations of tensile loading of nano-crystalline Al modeled by an embedded-atom method (EAM) potential. Usage of two different sample preparation methods of the nano-crystalline material allows us to compare mechanical properties for different sample qualities. A Voronoi-constructed polycrystal exhibits nearly no pores and has different mechanical properties compared to a material that is sintered under pressure and temperature from spherical nanoparticles, resulting in a lower-density sample. We found an inverse Hall-Petch relation for the flow stress for grain sizes smaller than 10 nm. Intergranular fracture was observed for the larger Al grain sizes, but not for nano-crystalline Cu. This article is based on a presentation given in the symposium “Dynamic Deformation: Constitutive Modeling, Grain Size, and Other Effects: In Honor of Prof. Ronald W. Armstrong,” March 2–6, 2003, at the 2003 TMS/ASM Annual Meeting, San Diego, California, under the auspices of the TMS/ASM Joint Mechanical Behavior of Materials Committee.