A method for calibrating the spatial coordinates of a visual display to high accuracy

High-resolution CRT displays are subject togeometric distortion: lines that are straight in the internal coordinates of the graphics software and hardware are curved when projected onto a plane in the observer’s line of sight. As the available resolution of CRT screens increases, it becomes more difficult to measure and correct for this distortion. We present a simple, highly accurate method for determining the mapping between internal coordinates and the viewing plane. It requires that an observer, using a calibration program, adjust triples of displayed points until they are collinear. A metal straightedge placed between the observer and the screen aids in this judgment. We describe the calibration of an IBM Enhanced Graphics Display in high-resolution mode (350 × 640 pixels), and illustrate how to use the estimated mapping to choose internal coordinates to draw undistorted figures that are accurate to within 0.5 pixel. The method can be used to assess or to correct the accuracy of visual displays. The method is relevant to experiments in spatial vision, spatial perception, perception of dot patterns, and any application in which geometrically accurate stimuli are required.     

Selection of software in the instructional laboratory

In this paper, I discuss a number of issues concerning software selection in instructional laboratories. First, I describe several taxonomies of instructional software and argue that the most important dimension of instructional software is that it must be an efficient tool. Second, I discuss some elements of the context of the instructional lab, including sophistication of users. Third, I explore design features, especially those related to ease of learning to use packages. Several other issues are also considered, such as where to find software reviews.     

A simulation-based tutorial system for exploring parallel distributed processing

This article presents a simulation-based tutorial system for exploring parallel distributed processing (PDP) models of information processing. The system consists of software and an accompanying handbook. The intent of the package is to make the ideas underlying PDP accessible and to disseminate some of the main simulation programs that we have developed. This article presents excerpts from the handbook that describe the approach taken, the organization of the handbook, and the software that comes with it. An example is given that illustrates the approach we have taken to teaching PDP, which involves presentation of relevant mathematical background, together with tutorial exercises that make use of the simulation programs.     

A critical evaluation of software for experiment development in research and teaching

This paper compares several software packages that allow users to create new computer-run experiments, but do not require that users be able to program. Three dimensions are considered: package requirements, ease of learning, and power and flexibility.     

Effects of observing competitive and violent versions of a sport

Males were randomly assigned to view either (1) a film clip featuring hockey fights or (2) a film of nonaggressive hockey action or (3) a no-film control condition after having first been angered or treated politely by an experimental confederate. The dependent variable was represented by a measure of aggressive mood and a behavioral measure of retaliatory aggression. Analyses revealed that both angered and nonangered subjects exhibited an increase in aggressive mood following exposure to the fight film. However, the analysis involving retaliatory aggression against the confederate yielded an anger x film interaction. While angered subjects were more aggressive than nonangered, only angered subjects retaliated against the confederate after viewing the fight film. The results were discussed in terms of Berkowitz’s (1974) aggressive cue theory. A version of this paper was presented at the meeting of the North American Society for the Sociology of Sport, Edmonton, Canada, November 1987.     

Converging evidence that fear of success is multidimensional

Fear of Success (FOS) was originally conceived as a unidimensional motive. However, there is both theoretical and empirical support for the hypothesis that FOS is multidimensional. We factor analyzed the responses of 236 undergraduates to twenty-oneConcern Over the Negative Consequences of Success items and found four factors. Our four factors show considerable overlap with dimensions based on theoretical accounts of FOS etiology as well as with the factor structures obtained from two other factor analytic studies. Thus, there is converging evidence that FOS is multidimensional. The relationship between multidimensional FOS and a multidimensional approach to achievement motivation is discussed.     

Maternal handling and motor development: an intracultural study

Citing a distinction between informal and formal routines used by mothers in handling their infants, we examined formal handling routines, in which the caregiver acts in a pedagogical manner; these routines are widespread in many non-Western countries. We hypothesised that formal handling serves to facilitate gross motor development during early infancy. To examine this hypothesis, the effects of a Jamaican formal handling routine on a broad range of developmental outcomes was examined. Results showed that the effects were specific to early gross motor development and in particular to postural control along the vertical axis of the body. Information is also provided on other aspects of Jamaican child care. It seems that the handling routine forms part of a folk (developmental) medicine system and may serve not only to promote child health but also as a sort of developmental neurological examination.     

Differences in school behavior and achievement between children from intact, reconstituted, and single-parent families.

Differences in school behavior and achievement between students from intact, reconstituted, and single-parent families were analyzed. Students from intact two-parent families had fewer absences and tardies, higher grade point averages, and fewer negative and more positive teacher behavioral ratings than did those from reconstituted and single-parent families.