Validation of a full body 3-D dynamic linked segment model

In studies related to human movement, linked segment models (LSM's) are often used to quantify forces and torques, generated in body joints. Some LSM's represent only a few body segments. Others, for instance used in studies on the control of whole body movements, include all body segments. As a consequence of the complexity of 3-dimensional (3-D) analyses, most LSM's are restricted to one plane of motion. However, in asymmetric movements this may result in a loss of relevant information. The aim of the current study was to develop and validate a 3-D LSM including all body segments. Braces with markers, attached to all body segments, were used to record the body movements. The validation of the model was accomplished by comparing the measured with the estimated ground reaction force and by comparing the torques at the lumbo-sacral joint that resulted from a bottom-up and a top-down mechanical analysis. For both comparisons, reasonable to good agreement was found. Sources of error that could not be analysed this way, were subjected to an additional sensitivity analysis. It was concluded that the internal validity of the current model is quite satisfactory.     

Problem–Problem Solver Characteristics Affectingthe Calibration of Judgments

The purpose of this paper is to examine factors that affect the calibration of judgments by systematically comparing experts’ judgments to novices’ when solving a complex, real-world problem that varies in its initial characteristics. Calibration in this context refers to the proportion of times decision makers provide a range about their best estimates that includes the actual outcome. We found that experts specify a narrower range and provide more accurate best estimates than novices. But their tighter ranges are not justified by their greater accuracy: they are less likely to encompass the actual outcome than are novices. However, this effect is attenuated when solving more complex problems. Novices apparently underestimate the complexity of difficult problems, hence the accuracy of their best estimates decreases as does the width of their ranges, resulting in worse calibration. The performance of experts was not significantly different across problem solving conditions. Both groups provided asymmetrical ranges about their best estimates, which suggests they account for the effect of subproblem dependencies.     

Comparing Risky Decision Making Under Conditions of Real and Hypothetical Consequences

In a series of three experiments, subjects made risky decisions under conditions of hypothetical or real consequences. Task variations across experiments included: (1) type of risk (monetary gambles or investments of time and effort), (2) within-subject and between-subjects manipulations of consequence condition, and (3) single or multiple decisions. The hypothesis of no difference between choices in real and hypothetical consequence conditions was retained in each experiment. Supplemental analyses ruled out various “artifactual” interpretations of the null results. Discussion focused on conditions in which researchers can and cannot infer decision makers’ actual risk preferences from their responses in laboratory tasks.     

Rationally developed fake-good and fake-bad scales for the Jesness Inventory

Develops two validity scales for the Jesness Inventory using a rational approach: a fake-good scale, Lie (L); and a fake-bad scale, Overt Symptomatology (OS). Effectiveness was assessed using 293 male delinquents classified as fake-good, fake-bad, or honest based on a matched-pair MMPI-A. L was moderately effective in detecting the fake-good set, and OS tentatively effective in detecting the fake-bad set. Both correlated well with their MMPI-A counterparts. Sensitivity, specificity, positive predictive power, negative predictive power, and overall effectiveness data were reported. The L scale and OS scale were related to race but differences were less than 1 raw score point. L was unrelated to age. OS was related to age, with younger children showing more willingness to admit to symptomatology. Age-based modified T-score norms were developed for the newly constructed scales using 1142 male and 360 female delinquents. ages 13–18.     

A short form of the Common Beliefs Survey III

Previous studies have shown that the Common Beliefs Survey III (CBS III) is an irrational beliefs inventory with satisfactory psychometric properties. We extended research on the CBS by examining this 54-item inventory for redundant material, and substantially abbreviated it without compormising its reliability or validity. This article describes the development of the new, 19-item short form (CBS19), convenient for clinical use, that preserves the psychometric properties of the original.     

Consider the source: One step in assessing premise acceptability

Premise acceptability is conceptually connected to presumption. To say that a premise is acceptable just when there is a presumption in its favor is to give a first approximation to this connection. A number of popular principles of presumption suggest that whether there is a presumption for a premise, belief, or claim depends on the sources which vouch for it. Sources consist of internal belief-generating mechanisms and external testimony. Alvin Plantinga's notion of warrant lays down four conditions upon a source for the belief which it generates to be warranted. We argue that there is a presumption for a premise, belief, or claim if and only if there is a presumption of warrant for that premise,belief or claim. This amounts to the thesis that there is a presumption for a belief from a challenger's point of view if and only if there is a presumption from that person's point of view that her cognitive faculties which have generated the belief have been functioning properly, in an appropriate cognitive environment, in accord with a segment of her design plan aimed at the truth, and that these faculties are reliable. In light of our argument for this thesis, we may legitimately claim that one way to determine that there is a presumption for a belief is to determine that there is a presumption of warrant for that belief, and thus that in determining whether there is a presumption for a belief or premise, we may consider the source.