A test of the circumvention-of-limits hypothesis in scientific problem solving: the case of geological bedrock mapping

Sources of individual differences in scientific problem solving were investigated. Participants representing a wide range of experience in geology completed tests of visuospatial ability and geological knowledge, and performed a geological bedrock mapping task, in which they attempted to infer the geological structure of an area in the Tobacco Root Mountains of Montana. A Visuospatial Ability × Geological Knowledge interaction was found, such that visuospatial ability positively predicted mapping performance at low, but not high, levels of geological knowledge. This finding suggests that high levels of domain knowledge may sometimes enable circumvention of performance limitations associated with cognitive abilities.     

Visual assessment of camouflaged targets with different background similarities

The study investigated the effectiveness of different camouflage designs using a computational image quality index. Camouflaged human targets were presented on a natural landscape and the targets were designed to be similar to the landscape background with different levels of background similarity as estimated by the image index. The targets were presented in front of the observer (central 0 degrees) or at different angles in the left (-7 degrees, -14 degrees, -21 degrees) or right (+7 degrees, +14 degrees, +21 degrees) visual fields. The observer had to detect the target using peripheral vision if the target appeared in the left and right visual fields. The camouflage effectiveness was assessed by detection hit rates, detection times, and subjective ratings on detection confidence and task difficulty. The study showed that the psychophysical measures correlated well with the image similarity index, suggesting a potentially more efficient camouflage effectiveness assessment tool if the relationship between the psychophysical results and the index can be quantified in the future.     

Reactions to a survey among those who were and were not sexually assaulted while serving in the military

Surveys are among the most common methods for evaluating military sexual assault experiences among members of the U.S. military; however, little research has examined how receiving surveys about such sexual assaults might affect recipients. In the present sample of 530 active duty and veteran military personnel, just 10% reported unexpected upset, 11% reported regretting participation in the survey, and 22% reported benefitting from that participation overall. A minority of respondents with a history of sexual assault while in the military reported unexpected upset, although the prevalence was three times higher than that of participants without such history (24% vs 8%). There were no statistically significant differences in perceived regret and benefit of participation in the survey between those with and without a history of sexual assault while in the military. Although limited in number, male military sexual assault survivors (n = 8) were significantly more likely than female survivors to report being more upset by the survey than they had anticipated. Implications for future research are discussed.     

Loud versus quiet praise: A direct behavioral comparison in secondary classrooms

The purpose of the present study was to compare the effects of teacher public (i.e., loud) and private (i.e., quiet) praise on students' appropriately engaged behavior (AEB) and disruptive behaviors (DB). Employing a combined multiple-baseline withdrawal design, the effects of loud and quiet praise were assessed across two pairs of secondary classrooms. Each classroom's mean percentage of observed intervals of AEB and DB across loud and quiet praise intervention phases was assessed and compared. Overall, visual analysis of the data, multilevel modeling, and effect sizes showed that both loud and quiet praises were more effective than no treatment at increasing AEB and decreasing DB. In addition, there were no statistical or clinically significant differences between the loud and quiet praise interventions. The results are discussed in light of appropriate practices and controversies in the literature.     

Keith Lehrer on Compatibilism

Keith Lehrer has been publishing on free will and compatiblism since 1960. Our concern here is to present an account of the development on his work on the subject.     

An analysis of U.S. parachuting fatalities: 2000-2004

Between 2000 and 2004, 125 recreational parachuting fatalities were reported in the USA. Each was categorized using a previously reported taxonomy. While patterns of skydiving fatality were largely unchanged since the last such analysis of fatalities from 1993-1999, some variations were noted. As in previous analyses, most of the recent skydiving fatalities were the direct result of human error. Some examples of commonplace human error fatalities were turning low to the ground resulting in a hard landing, accidentally colliding with other skydivers resulting in entangled parachutes, and failure to deploy the reserve parachute correctly in the event of malfunctioning main parachute.     

Verbal and cognitive distractors in driving performance while using hands-free phones

This study investigated the effect of different types of distractions related to use of a hands-free phone on driving performance. The study used three types of verbal distractors: casual conversation, simple arithmetic number guessing, and number adding, in the phone conversation. 12 adults were instructed to follow a lead vehicle on a closed-course highway in a fixed-based driving simulator. The results showed that use of a hands-free cellular phone involving verbal and cognitive distractions impaired driving performance and skill. Types of distraction produced significantly different effects on several dependent variables: the driving speed, headway (distance between the lead car and the manipulated car), brake reaction time, and number of collisions with the lead car. In general, the higher the cognitive load involved in the dialogue, the worse the driving performance.     

Minimalist semantics in meta-ethical expressivism

James Dreier (Philos Perspect 18:23–44, 2004) states what he calls the “Problem of Creeping Minimalism”: that metaethical Expressivists can accept a series of claims about meaning, under which all of the sentences that Realists can accept are consistent with Expressivism. This would allow Expressivists to accept all of the Realist’s sentences, and as Dreier points out, make it difficult to say what the difference between the two views is. That Expressivists can accept these claims about meaning has been suggested by Simon Blackburn on behalf of his “quasi-realist”. I argue against the assumption that there is a way to interpret the Realist’s sentences in a way that renders them consistent with Expressivism.