On the estimation of polychoric correlations and their asymptotic covariance matrix

A general theory for parametric inference in contingency tables is outlined. Estimation of polychoric correlations is seen as a special case of this theory. The asymptotic covariance matrix of the estimated polychoric correlations is derived for the case when the thresholds are estimated from the univariate marginals and the polychoric correlations are estimated from the bivariate marginals for given thresholds. Computational aspects are also discussed.The research was supported by the Swedish Council for Research in the Humanities and Social Sciences (HSFR) under the programMultivariate Statistical Analysis. The author thanks a reviewer for pointing out an error in the original version of the paper.     

A corpus of 714 full-color images of depth-rotated objects

A set of full-color images of objects is described for use in experiments investigating the effects of in-depth rotation on the identification of three-dimensional objects. The corpus contains up to 11 perspective views of 70 nameable objects. We also provide ratings of the “goodness” of each view, based on Thurstonian scaling of subjects’ preferences in a paired-comparison experiment. An exploratory cluster analysis on the scaling solutions indicates that the amount of information available in a given view generally is the major determinant of the goodness of the view. For instance, objects with an elongated front-back axis tend to cluster together, and the front and back views of these objects, which do not reveal the object’s major surfaces and features, are evaluated as the worst views.     

Johannes Daubert als Ästhetiker

Ohne Zusammenfassung     

Reduced K+ Channel Inactivation, Spike Broadening, and After-Hyperpolarization in Kvβ1.1-Deficient Mice with Impaired Learning

A-type K⁺ channels are known to regulate neuronal firing, but their role in repetitive firing and learning in mammals is not well characterized. To determine the contribution of the auxiliary K⁺ channel subunit Kvβ1.1 to A-type K⁺ currents and to study the physiological role of A-type K⁺ channels in repetitive firing and learning, we deleted the Kvβ1.1 gene in mice. The loss of Kvβ1.1 resulted in a reduced K⁺ current inactivation in hippocampal CA1 pyramidal neurons. Furthermore, in the mutant neurons, frequency-dependent spike broadening and the slow afterhyperpolarization (sAHP) were reduced. This suggests that Kvβ1.1-dependent A-type K⁺ channels contribute to frequency-dependent spike broadening and may regulate the sAHP by controlling Ca²⁺ influx during action potentials. The Kvβ1.1-deficient mice showed normal synaptic plasticity but were impaired in the learning of a water maze test and in the social transmission of food preference task, indicating that the Kvβ1.1 subunit contributes to certain types of learning and memory.     

Characteristics of Adult Caretakers of Children and Youth Served by an Urban Child Welfare Agency

The child welfare system of the early 1990s was marked by the proliferation of home-based services. Research on the effectiveness of various home-based interventions indicates results have been equivocal. The need to make explicit the specific characteristics of the adults and children targeted for home-based services, particularly families from diverse cultural backgrounds, has been identified as a critically needed contribution to the literature. In this study, the characteristics and service utilization experiences of adults and families served in an urban, home-based, child welfare program was examined. The results are discussed in relation to findings on the characteristics and experiences of adults and families served in other settings. Implications for future research and service delivery are discussed.     

Recognition times of different views of 56 depth-rotated objects: A note concerning Verfaillie and Boutsen (1995)

The present study examines the effect of thegoodness of view on the minimal exposure time required to recognize depth-rotated objects. In a previous study, Verfaillie and Boutsen (1995) derived scales of goodness of view, using a new corpus of images of depth-rotated objects. In the present experiment, a subset of this corpus (five views of 56 objects) is used to determine the recognition exposure time for each view, by increasing exposure time across successive presentations until the object is recognized. The results indicate that, for two thirds of the objects,good views are recognized more frequently and have lower recognition exposure times thanbad views.     

THEOLOGY IN AN EVOLUTIONARY MODE

Abstract. Evolution has become the standard way of understanding the world process. Theology has to express traditional faith in the context of the contemporary world. Since the common world view has profoundly changed, from a static world of being into a dynamic world of becoming, theology needs to change its language and its understanding of the universe as God's creation. This understanding of an evolving world is to be used as a theological source. Such a change of perspective necessitates a fundamental reconstructing of theology; for theology, such reconstructing means a renewed understanding of the Creator and of the Incarnation.     

PRAXIS: Brent’s algorithm for function minimization

Implementations of Brent’s (1973) PRincipal AXIS (PRAXIS) algorithm in the widely used C and PASCAL programming languages are presented. The algorithm minimizes a multivariate function without using derivatives. An example computer program that calculates a maximum likelihood estimate of the parameters of a psychometric function illustrates the use of the routine. Another algorithm, Localmin, also due to Brent (1973), efficiently finds the minimum of a univariate function. An example program uses this algorithm to estimate the polychoric correlation coefficient from a pxq table of observed frequencies.     

A method for utilizing a single port for multiple functions on the IBM PC or compatible system

Psychological experiments often require the control of a large number of output lines; unfortunately, the IBM PC provides only 32 8-bit ports through which communication may be implemented without risk of conflict with other software/hardware. A single 8-bit port may be used to control a large number of devices by adding appropriate decoder logic between the computer’s port and the devices that are to be controlled. Software and hardware are presented that illustrate this technique by controlling an 8-digit light-emitting diode display with a single IBM PC output port.     

The processing of inflected words

Summary Is an inflected word identified by first decomposing it into stem plus suffix or, instead, is it recognized as a whole? Several lexical decision experiments studied the recognition of inflected words in English (a language with few inflections) and Serbo-Croatian (a heavily inflected language). If recognition depended on decomposition, preceding the inflection with a brief exposure of the stem (<100 ms) should have primed the lexical entry for the stem and, therefore, facilitated recognition of the whole inflected word that followed. It did not. It was also found that the speed of recognizing an inflected word was more strongly associated with the frequency of the whole inflected form than with the frequency of its stem. The results suggested that in word recognition, lexical contact is first made with the whole word form. Nevertheless, morphological decomposition may still occur in subsequent processing.