Covariance structure analysis in several populations

This paper is concerned with the study of covariance structural models in several populations. Estimation theory of the parameters that are subject to general functional restraints is developed based on the generalized least squares approach. Asymptotic properties of the constrained estimator are studied; and asymptotic chi-square tests are presented to evaluate appropriate model comparisons. The method of multipliers and the standard reparametrization technique are discussed in obtaining the estimates. The methodology is demonstrated by a set of real data.Computer facilities were provided by the Computer Services Center, The Chinese University of Hong Kong. The authors are indebted to several anonymous reviewers for suggestions for improvement of this paper.     

Drawing Movements as an Outcome of the Principle of Least Action

According to the two-thirds power law the cube of the speed of a drawing movement is proportional to the radius of curvature of the trajectory, and the coefficient of proportionality has the meaning of mechanical power. We derive this empirical law from the variational principle known in physics as the principle of least action. It states that if a movement between two points of a given path obeys the two-thirds law, then the amount of work required to execute a trajectory in a fixed time is minimal. In this strict sense one may say that among infinitely many ways to execute a given path, the central nervous system chooses the most economical. We show that the kinematic equations for all drawing movements are solutions of a certain differential equation with a single (time-variable) coefficient. We consider several special cases of drawing movements corresponding to simplest forms of this coefficient. Copyright 2001 Academic Press.     

Bimodal emotion congruency is critical to preverbal infants’ abstract rule learning

Extracting general rules from specific examples is important, as we must face the same challenge displayed in various formats. Previous studies have found that bimodal presentation of grammar‐like rules (e.g. ABA) enhanced 5‐month‐olds’ capacity to acquire a rule that infants failed to learn when the rule was presented with visual presentation of the shapes alone (circle‐triangle‐circle) or auditory presentation of the syllables (la‐ba‐la) alone. However, the mechanisms and constraints for this bimodal learning facilitation are still unknown. In this study, we used audio‐visual relation congruency between bimodal stimulation to disentangle possible facilitation sources. We exposed 8‐ to 10‐month‐old infants to an AAB sequence consisting of visual faces with affective expressions and/or auditory voices conveying emotions. Our results showed that infants were able to distinguish the learned AAB rule from other novel rules under bimodal stimulation when the affects in audio and visual stimuli were congruently paired (Experiments 1A and 2A). Infants failed to acquire the same rule when audio‐visual stimuli were incongruently matched (Experiment 2B) and when only the visual (Experiment 1B) or the audio (Experiment 1C) stimuli were presented. Our results highlight that bimodal facilitation in infant rule learning is not only dependent on better statistical probability and redundant sensory information, but also the relational congruency of audio‐visual information. A video abstract of this article can be viewed at https://m.youtube.com/watch?v=KYTyjH1k9RQ     

Outcome Knowledge and Under‐reporting of Safety Concerns in Aviation

High‐risk industries may learn from accidents, incidents and unsafe behaviours if they are reported and investigated. Despite this, significant under‐reporting of safety concerns occurs. One possible explanation is that because concerns cannot always be reported immediately, the outcome of the concern may influence whether reports are made. In Study 1, participants judged six vignettes in which unsafe acts were described: bad outcomes were judged as more likely to be reported than identical acts with innocuous outcomes. Informing participants that luck may determine whether an outcome is innocuous or bad could increase the reporting of unsafe acts with innocuous outcomes. Although implicit prompts did not increase the likelihood of reporting innocuous outcomes (Study 2), there was evidence that explicit prompts to report safety issues with innocuous outcomes increased the likelihood of reporting. Suggestions for further research and a means to reduce the effect of outcome bias on under‐reporting are presented. Copyright © 2015 John Wiley & Sons, Ltd.     

Statistical inference for multiple choice tests

Finite sample inference procedures are considered for analyzing the observed scores on a multiple choice test with several items, where, for example, the items are dissimilar, or the item responses are correlated. A discrete p-parameter exponential family model leads to a generalized linear model framework and, in a special case, a convenient regression of true score upon observed score. Techniques based upon the likelihood function, Akaike's information criteria (AIC), an approximate Bayesian marginalization procedure based on conditional maximization (BCM), and simulations for exact posterior densities (importance sampling) are used to facilitate finite sample investigations of the average true score, individual true scores, and various probabilities of interest. A simulation study suggests that, when the examinees come from two different populations, the exponential family can adequately generalize Duncan's beta-binomial model. Extensions to regression models, the classical test theory model, and empirical Bayes estimation problems are mentioned. The Duncan, Keats, and Matsumura data sets are used to illustrate potential advantages and flexibility of the exponential family model, and the BCM technique.The authors wish to thank Ella Mae Matsumura for her data set and helpful comments, Frank Baker for his advice on item response theory, Hirotugu Akaike and Taskin Atilgan, for helpful discussions regarding AIC, Graham Wood for his advice concerning the class of all binomial mixture models, Yiu Ming Chiu for providing useful references and information on tetrachoric models, and the Editor and two referees for suggesting several references and alternative approaches.     

The Effects of Gender,Education, and Personal Skills Self-Confidence on Income in Business Management

A pay disparity between men and women persists,especially in the higher echelons of the business world.This study investigates whether salaries in the businessmanagement field are affected by gender, hours worked, SAT score, college selectivity,college grades, an undergraduate degree in business,graduate degree attainment, leadership self-confidence,and social self-confidence. The sample consists of 941 men and women employed in businessmanagement; approximately 8% of this group are racialminority members. As anticipated, hours worked, collegeselectivity, college grades, a graduate degree, and leadership self-confidence are determinants ofincome. Most important is the finding that aftercontrolling for hours worked, education background, andself-confidence in personal skills, men still receive higher salaries than women.     

Effect of lie labelling on children's evaluation of selfish,polite, and altruistic lies

This study investigates how 5‐ and 6‐year‐olds' evaluations of selfish, polite, and altruistic lies change as a result of whether these false statements are explicitly labelled as lies. We are also interested in how interpretive theory of mind may correlate with such evaluations with and without a lie label. Our results showed that labelling lowered children's evaluations for the polite and altruistic lies, but not for the selfish lies. Interpretive theory of mind correlated positively with the evaluation difference between the polite and altruistic lies and that between the selfish and altruistic lies in the label, but not in the non‐label condition. Correlation between the selfish and altruistic lies and that between the polite and altruistic lies were stronger with than without labelling, after controlling for age, and verbal and non‐verbal intelligence. We conclude that lie labelling biases children towards more negative evaluations for non‐selfish lies and makes them see lies of different motives as more similar. If a lie label is applied, whether lies of different motives are still evaluated differently depends on interpretive theory of mind, which reflects the child's ability to represent and allow different interpretations of an ambiguous reality.     

Serotonin mediates a learned increase in attraction to high concentrations of benzaldehyde in aged C. elegans

We utilized olfactory-mediated chemotaxis in Caenorhabditis elegans to examine the effect of aging on information processing and animal behavior. Wild-type (N2) young adults (day 4) initially approach and eventually avoid a point source of benzaldehyde. Aged adult animals (day 7) showed a stronger initial approach and a delayed avoidance to benzaldehyde compared with young adults. This delayed avoidance is due to an increased attraction rather than a decreased avoidance to benzaldehyde because (1) aged odr-3 mutants that are defective in odor attraction showed no delayed benzaldehyde avoidance, and (2) the delay in avoidance was also observed with another attractant diacetyl, but not the repellent octanol. Interestingly, the stronger expression of attractive behavior was only observed at benzaldehyde concentrations of 1% or higher. When worms were grown on nonbacterial growth media instead of Escherichia coli, thus removing the contingency between odors released from the food and the food itself, the increase in attraction to benzaldehyde disappeared. The increased attraction recovered after reinitiating the odor-food contingency by returning animals to E. coli food or supplementing axenic media with benzaldehyde. Moreover, serotonin-deficient mutants showed a deficit in the age-enhanced attraction. These results suggest that the increased attraction to benzaldehyde in aged worms is (1) serotonin mediated, (2) specific to high concentration of odorants, and (3) dependent on a learned association of odor metabolites with the presence of food. We propose that associative learning may selectively modify pathways at or downstream from a low-affinity olfactory receptor.