The relationship between treatment exposure times and changes in stuttering frequency during contingent stimulation

Four adult stutterers were exposed to 60 consecutive minutes of verbal contigent stimulation. In each session subjects spoke until a stuttering frequency stability criterion was met (baserate) followed by 60 min of exposure to the word wrong presented contingently upon each instance of stuttering. The data were analyzed according to changes in stuttering which occured following 20, 40, and 60 min of treatment exposure. The results revealed that stuttering frequency was reduced for all subjects during all three 20-min segments of the treatment condition. The only significant reductions in stuttering frequency, however, occured within the first 20 min of treatment.     

Changing expectations: A longitudinal study of community attitudes toward a nuclear power plant

Initial and 5-year follow-up interviews were conducted with 213 residents of the host community for a nuclear power plant. The purpose was to determine possible changes in attitudes toward the plant and expectations about potential outcomes associated with construction. Large negative changes in attitudes toward the plant were noted and were accompanied most notably by decreased expectations of positive outcomes. The structure of the expectations remained essentially stable over the 5-year period. Perceptions of hazards, community disruption, and economic benefits as measured early in construction and during peak construction were found to be the best predictors of acceptance of the nuclear plant. Initial expectations were found to predict overall attitude toward the plant 5 years later. Results were discussed in terms of implications for social impact assessment, large-scale community change, and the predictability of community attitudes toward nuclear power plant construction.     

A Bayesian random effects model for testlets

Standard item response theory (IRT) models fit to dichotomous examination responses ignore the fact that sets of items (testlets) often come from a single common stimuli (e.g. a reading comprehension passage). In this setting, all items given to an examinee are unlikely to be conditionally independent (given examinee proficiency). Models that assume conditional independence will overestimate the precision with which examinee proficiency is measured. Overstatement of precision may lead to inaccurate inferences such as prematurely ending an examination in which the stopping rule is based on the estimated standard error of examinee proficiency (e.g., an adaptive test). To model examinations that may be a mixture of independent items and testlets, we modified one standard IRT model to include an additional random effect for items nested within the same testlet. We use a Bayesian framework to facilitate posterior inference via a Data Augmented Gibbs Sampler (DAGS; Tanner & Wong, 1987). The modified and standard IRT models are both applied to a data set from a disclosed form of the SAT. We also provide simulation results that indicates that the degree of precision bias is a function of the variability of the testlet effects, as well as the testlet design.The authors wish to thank Robert Mislevy, Andrew Gelman and Donald B. Rubin for their helpful suggestions and comments, Ida Lawrence and Miriam Feigenbaum for providing us with the SAT data analyzed in section 5, and to the two anonymous referees for their careful reading and thoughtful suggestions on an earlier draft. We are also grateful to the Educational Testing service for providing the resources to do this research.     

Relational Considerations in the Use of Influence Tactics1

It is proposed that the existing relationship between the influencing agent and the target of influence plays a central role in the choice of using hard and soft influence tactics. In a field study, 3 key aspects of the relation between agent and target were examined, and the results generally supported our hypotheses. First, the more unfairly people felt they were treated, the more often they wielded influence, especially using harder influence tactics. Second, the better the influencing agent liked the target, the relatively less often he or she used hard tactics. Finally, the more the influencing agent felt dependent upon the target, the fewer influence tactics, both hard and soft, were used. The discussion focuses on both the practical and theoretical implications of these findings.     

Goal-Directed Aiming: Correcting a Force-Specification Error With the Right and Left Hands

In 2 experiments, the authors examined manual aiming asymmetries as well as the ability of participants to adjust their aiming trajectories following an unexpected change to the inertial resistance to movement. In Experiment 1, participants (N = 11) were able to rapidly adjust their movement trajectories to conform to the new movement requirements. They were faster and more consistent when aiming with their right hand than with their left hand, regardless of whether or not the movement was perturbed. In Experiment 2, participants' (N = 11) vision of the hand was manipulated so that the role of visual feedback in the corrective process could be examined. Vision had an impact not only on performance but also on the characteristics of the movement trajectories. Manual asymmetries in aiming were associated with a right hand superiority during the final corrective stages of the movement.     

Timing the Selection of Information During Rhythmic Catching

Catching a ball requires that information be available close to the catch but early enough for prospective or corrective control. In the present experiment, 6 participants were asked to throw and catch a ball continuously for 1 min while wearing liquid-crystal goggles that restricted viewing to specific amounts of time at specific intervals. Participants were free to select the information by varying the frequency and phasing of throwing relative to the goggles. Video analysis revealed that they elected a frequency of throwing that matched the goggle frequency and chose to view the ball at or around its zenith. Earlier portions of the ball's trajectory were viewed as the goggle frequency increased. Despite variations in the viewing location, participants elected to view the ball on average 365 ms before the catch. Analysis of the hand's trajectory further revealed that the time interval (M = 82 ms) between the ball's zenith and the initiation of the final motion of the hand toward the catch did not vary as a function of the frequency of throwing. The authors conclude that the timing constraints imposed by the hand's movement are the basis for the selection of information for catching.     

STRESS, SOCIAL SUPPORT, AND HEALTH IN MARRIED PROFESSIONAL WOMEN WITH SMALL CHILDREN

Two hundred married professional women with small children were surveyed to investigate what types of occupational and role-conflict stresses are associated with physical and depressive symptoms, and whether social support could protect individuals from the negative health effects of stress. Six stress indices predicted physical and depressive symptoms, both Concurrently and 1 year later. These stresses reflected perceptions of lack of authority and influence on the job, sex discrimination, a heavy work load, work imposing on relaxation, family imposing on relaxation, and overall suffering from role conflict. Social support yielded no stress-buffering effects.