A rasch model for continuous ratings

A unidimensional latent trait model for continuous ratings is developed. This model is an extension of Andrich's rating formulation which assumes that the response process at latent thresholds is governed by the dichotomous Rasch model. Item characteristic functions and information functions are used to illustrate that the model takes ceiling and floor effects into account. Both the dichotomous Rasch model and a linear model with normally distributed error can be derived as limiting cases. The separability of the structural and incidental parameters is demonstrated and a procedure for estimating the parameters is outlined.     

Convergence of parent checklists and child psychiatric diagnoses

This study examined the correlation between the Childrens' Behavior Questionnaire by Rutter, Tizard, and Whitmore (1970) and clinical diagnoses in a total of 1,468 in-and outpatients. The following diagnoses were considered: conduct disorder, emotional disorder, mixed disorder of conduct and emotions, and the hyperkinetic syndrome. In general, correlations were low, but subscores indicating conduct or neurotic disorders had somewhat higher correlation with these respective disorders than the hyperactivity subscore. Sensitivity figures (i.e., percentage of true positives) were moderate to low, while specificity figures (i.e., percentage of true negatives) were high. It is concluded that convergence of parent checklists and child psychiatric diagnoses in unselected samples is only moderate.     

Intersensory facilitation in the motor component?

Summary In the bimodal detection task the observer must respond as soon as a signal is presented in either of two modalities (e.g., a tone or a flash). A typical finding is a facilitation of reaction time for redundant signal trials, that is, when both signals are presented simultaneously or with a short delay. Models advanced for this effect imply either statistical facilitation (separate activation) or intersensory facilitation (coactivation). This paper reports a study investigating whether part of the facilitation can be accounted for by coactivation in the motor component. An analysis of the distributions of reaction time differences between left and right hand responses from a double response paradigm gave some evidence in favor of this hypothesis. In particular, our data suggest a u-shaped functional dependence of the amount of facilitation in the motor component on the interstimulus interval.     

Criterion-related validity of self-report measures of female heterosocial functioning

Common measures of female heterosocial functioning, the Survey of Heterosocial Interactions for Females (SHI-F) and dating frequency questions, were validated against the criterion of male liking, i. e., how well men like a woman. The SHI-F was unrelated to the criterion and to the other measures of heterosocial activity. The dating frequency and satisfaction questions were moderately related to the criterion. It was concluded the self-reported ability to initiate contact with men (as measured by the SHI-F) may not be related to female heterosocial functioning. Self-reported dating frequency and satisfaction appear to be a valid measure of female heterosocial functioning.The data were collected while the first author was at Louisiana State University.     

A jiffy clock for the Apple IIc,II+, and IIe with a mouse

A “jiffy clock” is presented for the Apple lIc or other Apple II having Apple’s mouse card. The clock allows timing of events to tenths of a second, and is read from BASIC. A convenient elapsed timer function is provided as well.     

Kants Kritik der reinen Vernunft Ein Grundbuch der modernen Philosophie

Zusammenfassung Kants kritische Philosophie hat Epoche gemacht. Sie bildet den Höhepunkt der neuzeitlichen Aufklärung. Mit der Kritik der reinen Vernunft hat Kant ein klassisches Werk geschaffen, das noch heute als Grundbuch der neueren Philosophie angesehen werden muss. Es erörtert die Möglichkeiten und Grenzen der menschlichen Vernunft und entwickelt dabei die normativen Grundlagen unseres Erfahrungswissens ebenso wie der wissenschaftlichen Erkenntnis. Der Beitrag gibt einen Überblick über Inhalt, Perspektiven und Bedeutung dieses Werkes und sucht zu verdeutlichen, inwiefern es Massstäbe für alle theoretischen wie praktischen Bereiche unseres Wissens gesetzt hat, die bis heute bestimmend geblieben sind.     

Understanding movement control in infants through the analysis of limb intersegmental dynamics

One important component in the understanding of the control of limb movements is the way in which the central nervous system accounts for joint forces and torques that may be generated not only by muscle actions but by gravity and by passive reactions related to the movements of limb segments. In this study, we asked how the neuromotor system of young infants controls a range of active and passive forces to produce a stereotypic, nonintentional movement. We specifically analyzed limb intersegmental dynamics in spontaneous, cyclic leg movements (kicking) of varying intensity in supine 3-month-old human infants. Using inverse dynamics, we calculated the contributions of active (muscular) and passive (motion-dependent and gravitational) torque components at the hip, knee, and ankle joints from three-dimensional limb kinematics. To calculate joint torques, accurate estimates were needed of the limb's anthropometric parameters, which we determined using a model of the human body. Our analysis of limb intersegmental dynamics explicitly quantified the complex interplay of active and passive forces producing the simple, involuntary kicking movements commonly seen in 3-month-old infants. our results revealed that in nonvigorous kicks, hip joint reversal was the result of an extensor torque due to gravity, opposed by the combined flexor effect of the muscle torque and the total motion-dependent torque. The total motion-dependent torque increased as a hip flexor torque in more vigorous kicks; an extensor muscle torque was necessary to counteract the flexor influences of the total motion-dependent torque and, in the case of large ranges of motion, a flexor gravity torque as well. Thus, with changing passive torque influences due to motions of the linked segments, the muscle torques were adjusted to produce a net torque to reverse the kicking motion. As a consequence, despite considerable heterogeneity in the intensity, range of motion, coordination, and movement context of each kick, smooth trajectories resulted from the muscle torque, counteracting and complementing not only gravity but also the motion-dependent torques generated by movement of the linked segments.     

Technology: Autonomous or neutral

Two conflicting visions of technology nevertheless agree that scientists and engineers bear little moral responsibility for their inventions. According to one vision, technology is largely autonomous,” that is, self‐determinative operating according to its own blind laws independently of human will. According to the other, technology is fully controllable, but control rests solely with ‘end‐users’ as technology is, in itself, value‐neutral. After a brief characterization of the domain of technology, each vision of technology is criticized in turn. Despite the many penetrating insights offered by the best exemplar of the first approach— Jacques Ellul—it is shown that his approach rests on unacceptable metaphysical and epis‐temological assumptions: because it seemingly explains so much, it explains nothing; and it anthropomorphizes technology. Champions of the value neutrality thesis fail to sustain their argument because they overlook the ways in which various technologies embody the values of particular persons, institutions, or classes. Undermining these two prominent visions of technology opens the way for afresh consideration of the moral responsibilities of the creators and users of technology.