Jennifer A. Stillman

What Happens Next? The Predictability of Natural Behaviour Viewed through CCTV Cameras

Can potentially antisocial or criminal behaviour be predicted? Our study aimed to ascertain (a) whether observers can successfully predict the onset of such behaviour when viewing real recordings from CCTV; (b) where, in the sequence of events, it is possible to make this prediction; and (c) whether there may be a difference between naïve and professional observers. We used 100 sample scenes from UK urban locations. Of these, 18 led to criminal behaviour (fights or vandalism). A further 18 scenes were matched as closely as possible to the crime examples, but did not lead to any crime, and 64 were neutral scenes chosen from a wide variety of noncriminal situations. A signal-detection paradigm was used in conjunction with a 6-point rating scale. Data from fifty naïve and fifty professional observers suggest that (a) observers can distinguish crime sequences from neutral sequences and from matches; (b) there are key types of behaviour (particularly gestures and body position) that allow predictions to be made; (c) the performance of naïve observers is comparable to that of experts. However, because the experts were predominantly male, the absence of an effect of experience may have been due to gender differences, which were investigated in a subsidiary experiment. The results of experiment 2 leave open the possibility that females perform better than males at such tasks.

Rating Tasks Versus Dimensions in Assessment Centers: A Psychometric Comparison

Assessment centers (ACs) have been widely criticized on the basis of measurement problems throughout the literature dating back to 1982. This study investigates whether an alternative to the prevailing trait paradigm would provide a more sensible treatment of AC ratings. All data were obtained in a real-world AC from the behavioral responses of 187 participants. Two paradigms of assessment were compared in a repeated measures design. The first model treated the AC data as though they comprised situationally specific behavioral samples. The second, more traditional model treated the data as though they were indicative of trait-based responses. Using generalizability theory, factor analysis, and confirmatory factor analysis, both models demonstrated similar psychometric characteristics, although only data treated under the situationally specific model held a conceptual justification in this study. These findings suggest that the situationally specific task-based model presents a more appropriate means by which to treat AC ratings in practice.

A 30-year follow-up of residual effects on New Zealand School Dental Nurses, from occupational mercury exposure:

This paper reports possible residual adverse effects from occupational mercury exposure in dentistry, Thirty years ago, the all-women exposed group worked with both silver and copper amalgam filling material without protective gloves or a ventilation system, resulting in chronic mercury exposure. The aim of the study was to test the null hypothesis in a survey of general and reproductive health, and a battery of nine neurobehavioral tests. The population was the 115 graduates of one school for dental nurses from 1968 to 1971. The sample was 43 mercury-exposed women and 32 matched controls. Statistical comparisons revealed that the two groups were equivalent on cognitive tasks and four of the six mood subscales. Significant between-group differences were found in current health symptom experience and reproductive health, especially early hysterectomy experience. Reporting of Occupational Overuse Syndrome was strongly positively correlated with years of work. In general, the study suggests that acute symptoms from mercury exposure may be reversible, while some residual health effects may be becoming more of a concern with the womens increasing age. Human & Experimental Toxicology (2007) 26, 367—374

The Use of Process Mnemonics in Teaching Students with Mathematics Learning Disabilities.

This study investigated the effects of process mnemonic (PM) instruction on the computational skills performance of 13- to 14-year-old students with mathematics learning disabilities. Two experiments are described. In Experiment 1, 29 students were randomly assigned to one of four instruction groups: PM, demonstration-imitation (DI), study skills (SS), or no instruction (NI). In Experiment 2, instructors with no vested interest in the outcomes of the study were employed to teach 28 students who were assigned to PM, DI, or NI groups. Both PM and DI students made significant improvements in addition, subtraction, multiplication, and division. However, improvements were often greater for PM students. More importantly, the improvements made by PM students maintained better than those of DI students over six-week (Experiment 1) and eight-week (Experiment 2) follow-up periods.

Gustation: Intersensory Experience Par Excellence

On the face of it, basic tactile sensation might seem the only essential sensory requirement for the delivery of foods and beverages to the digestive system. In practice, however, the appropriate delivery of raw materials for the maintenance and repair of the body requires complex sensory and cognitive processes, such that flavour sensation arguably constitutes the pre-eminent example of an integrated multicomponent perceptual experience. To raise the profile of the chemical senses amongst researchers in other perceptual domains, I review here the contribution of various sense modalities to the flavour of foods and beverages. Further, in the light of these multisensory inputs, the physiological and psychophysical research summarised in this paper invites optimism that novel ways will be found to intervene when nutritional status is compromised either by specific dietary restraints, or by taste and smell disorders.

Task-Based Assessment Centers: Empirical Support for a Systems Model

Task-based assessment centers (TBACs) have been suggested to hold promise for practitioners and users of real-world ACs. However, a theoretical understanding of this approach is lacking in the literature, which leads to misunderstandings. The present study tested aspects of a systems model empirically, to help elucidate TBACs and explore their inner workings. When applied to data from an AC completed by 214 managers, canonical correlation analysis revealed that extraversion, abstract reasoning, and verbal reasoning, conceptualized as inputs into a system, explained around 21% of variance in manifest assessment center behavior. Behavior, in this regard, was found to consist of both general and situationally specific elements. Results are discussed in terms of their support for a systems model and as they pertain to the literature on TBACs.

When Traits Are Behaviors: The Relationship Between Behavioral Responses and Trait-Based Overall Assessment Center Ratings

Interest in exercise effects commonly observed in assessment centers (ACs) has resurfaced with Lance, Lambert, Gewin, Lievens, and Conways 2004 study. The study presented here addressed the construct validity puzzle associated with ACs by investigating whether traditional trait-based overall assessment ratings (OARs) could be explained by behavioral performance on exercises. In a sample of 208 job applicants from a real-world AC, it was found that the multivariate combination of scores from three behavioral checklists explained around 90% (p < .001) of the variance in supposedly trait-based OARs. This study adds to the AC literature by suggesting that traditional OARs are predictive of work outcomes because they reflect exercise-specific behavioral performance rather than trait-based assessments. If this is the case, validity and efficiency are best served by abandoning redundant trait ratings (dimensions) in favor of more direct behavioral ratings.

Frame of Reference Training for Assessment Centers: Effects on Interrater Reliability When Rating Behaviors and Ability Traits

Assessment centers have been widely criticized on the basis of measurement problems. The present study sought to present a methodological piece on the extent to which Frame of Reference (FOR) training would increase the interrater reliability associated with assessment center ratings provided by non-psychologist assessors. Five managerial assessors (with no psychological training) rated the behavior and the ability traits of a contrived participant on the basis of behaviors described in two alternative vignettes (detailing critical incidents of job performance). The ratings were obtained both before and following FOR training. It was found that agreement among assessors on their assessment of both behaviors and traits increased subsequent to the FOR training procedure. The implications of increasing the precision associated with assessment center ratings are discussed.

Influence of sensitivity on response bias in taste and audition

A detection theoretic analysis was employed to examine sensitivity and response bias in two modalities. In Experiment 1, 6 tasters made same-different judgments about the concentration of either sucrose or quinine in pairs of tonic water samples. The beverages were colored, but color was not predictive of the concentration of the sweet or bitter ingredient. When same-different ratings were collapsed to approximate the outcome of a categorical decision, tasters with poorer sensitivity appear to have adopted more extreme response criteria than did tasters with greater sensitivity, irrespective of taste quality, color, or whether pairs of solutions comprised the same or different colors. In Experiment 2, 3 individuals discriminated pairs of 1000-Hz sinusoids differing in amplitude. Six amplitude differences were tested. Rating-scale versions of two paradigms: The single-interval yes-no task and the two-interval same-different task were used to measure sensitivity and bias. There was a preponderance of “same” responses in the same-different task. Estimates of bias obtained from collapsed ratings in both tasks were unaffected by sensitivity, but a consideration of the range over which sets of criteria were spread suggested a general tendency toward more conservative response biases as sensitivity declined.

A computer-controlled electrogustometer for the estimation of evoked taste thresholds

Reliable taste detection thresholds in humans are difficult to obtain for either research or clinical purposes because ordinary taste stimuli cannot be generated and presented by means of a computer. However, in investigations of taste dysfunction, electrical taste stimulation (electrogustometry) is sometimes employed. Minute anodal direct currents are applied manually to the tongue, giving rise to an acid taste experience through the liberation of protons into the saliva. This experience accords with recent findings on the mechanisms underlying sour taste perception. The device described here is a safe and accurate constant-current device, operating under computer control at very low amperages, making it possible to apply modern psychophysical procedures to the measurement of evoked taste thresholds.