Factor analysis by minimizing residuals (minres)

This paper is addressed to the classical problem of estimating factor loadings under the condition that the sum of squares of off-diagonal residuals be minimized. Communalities consistent with this criterion are produced as a by-product. The experimental work included several alternative algorithms before a highly efficient method was developed. The final procedure is illustrated with a numerical example. Some relationships of minres to principal-factor analysis and maximum-likelihood factor estimates are discussed, and several unresolved problems are pointed out.The authors wish to thank the Factor Analysis Work Group (supported, in part, by ONR) for valuable criticisms and suggestions made in the course of a discussion of the present work in April, 1965.     

Disruption of proofreading by irrelevant speech: Effects of attention,arousal or memory?

A series of five experiments examined the effects of irrelevant speech on proofreading and memory. Four of the experiments used a proofreading task and showed that the deleterious effects of irrelevant speech: (1) depend on the speech being meaningful, (2) are only present when the burden on short-term memory is low and (3) are manifested in a lower detection rate for non-contextual as opposed to contextual errors. Neither the spatial location of the speech (either in terms of spatial dispersion of sources or spatial movement of a single source) nor the intensity of the speech (in a range bounded by 50 dB(A) and 70 dB(A)) had any effect on proofreading. Late selection models of attention are favoured by the results in preference to models having arousal, short-term memory or early selection in attention as their basis. A final experiment showed serial recall for visual lists to be impaired by the presence of any speech-like sound (including reversed speech and speech in an unfamiliar language) which suggests a set of phenomena qualitatively different from those associated with proofreading. Throughout the article the practical consequences of the findings are emphasized.     

Safety locus of control and employees' accidents

This study further established the criterion-related validity of the Safety Locus of Control Scale. The safety scale was designed to predict employment applicants' propensity for on-the-job accidents. In this study, 283 hospital employees with moreexternal safety locus of control orientations reported significantly more occupational accidents, as well as more severe and costly injuries, than workers with moreinternal safety attitudes (p<.05 in all cases). Implications of these results are discussed.Research study presented at the 1988 Annual Conference of the Association of Human Resources Management and Organizational Behavior, Long Beach, California, October 26–29.     

The influence of perceptual and motor factors on bimanual coordination in a polyrhythmic tapping task

Summary In this study the role of perceptual and motor factors on the motor organization (integrated versus parallel) adopted by musically skilled and unskilled subjects in a polyrhythmic tapping task was investigated. Subjects tapped a 3:2 polyrhythm to match the timing of two isochronous tone trains, one tone train for each hand. Perceptual factors were examined by the manipulation of the frequency difference between the tone trains to produce either an integrated or a streamed percept. Motor factors were examined by comparison of performance on two versions of the 3:2 polyrhythm. In one (simultaneous) version, each cycle of the polyrhythm began with a simultaneous left- and right-hand tap. In the other (shifted) version a 100-ms interval was introduced between the initial left and right taps in each cycle. Examination of the pattern of variances and covariances among intertap intervals suggested that most of the subjects in this study adopted an integrated motor organization that involved interleaving the timing of the two hands. Further analysis revealed that a serial chained model described the pattern of covariances best for the simultaneous pattern, whereas a hierarchical organization described the pattern of covariances for the shifted pattern best. The finding that performance was more accurate with integrated tones than with streamed tones provides some support for a perceptual-motor facilitation hypothesis.     

Reducing adverse reaction to stress in the workplace. Psychology's expanding role

This section draws attention to occupational stress and suggests ways in which psychologists can apply their knowledge of research methods and treatment to this issue. In this article, the past and present role of psychologists in occupational stress is examined and ways in which psychologists might play a more central role are proposed. Although industrial/organizational and health psychology are most obviously applicable to the study of workplace wellness, more focused attention and wider application of knowledge from other subspecialities are also examined. The need for increased attention to work and family; race, class, and gender; and training and public policy issues are also discussed.     

On the distinction between artifacts and information

Sperling, Landy, Dosher, and Perkins (1989) argued that all previous research on the kinetic depth effect has been contaminated by stimulus artifacts, and they developed a new task that they believe can successfully overcome this problem. The present discussion offers a counter-argument that artifacts are not as pervasive in previous research as Sperling et al. imply and that their proposed method is subject to precisely the same limitations as earlier studies. Also discussed are some general guidelines of experimental design in this type of research to minimize the possibility that subjects will adopt an inappropriate response strategy that does not truly reflect their visual perceptions of three-dimensional form.     

Visual perception of smoothly curved surfaces from double-projected contour patterns

This research was designed to examine how human observers are able to perceive the 3-dimensional structure of smoothly curved surfaces from projected patterns of surface contours. Displays were generated by using a method of double projection that made it possible to cover a surface with a wide range of contour patterns of varying geometric structure and to eliminate systematic variations of image shading. The compelling impression of 3-dimensional form from these patterns provides strong evidence that the ability of observers to perceptually interpret surface contours is considerably less restrictive than would be reasonable to expect on the basis of existing computational models. Results suggest that the perceptual analysis of surface contours is able to exploit statistical regularities of contour structure over appropriately large regions of visual space.