The information conveyed by words in sentences

A method is presented for calculating the amount of information conveyed to a hearer by a speaker emitting a sentence generated by a probabilistic grammar known to both parties. The method applies the work of Grenander (1967) to the intermediate states of a top-down parser. This allows the uncertainty about structural ambiguity to be calculated at each point in a sentence. Subtracting these values at successive points gives the information conveyed by a word in a sentence. Word-by-word information conveyed is calculated for several small probabilistic grammars, and it is suggested that the number of bits conveyed per word is a determinant of reading times and other measures of cognitive load.     

Effects of Interspersing Additional Brief Math Problems on Student Performance and Perception of Math Assignments: Getting Students to Prefer to Do More Work

Three experiments were conducted to assess the effects of the interspersing procedure on students' mathematics performance, perceptions of mathematics assignments, and preference for mathematics assignments when more work was added. In Experiment I, college students worked computation problems from two assignments. The control assignment contained 15 three-digit by two-digit problems (3 × 2) and the experimental assignments contained 18 3 × 2 problems and 6 additional interspersed one-digit by one-digit problems (1 × 1). Students then rated the assignments and chose one for homework. Results showed significantly more students preferred (i.e., chose it for homework) the experimental assignment with the additional target (i.e., 3 × 2) and interspersed problems. Furthermore, significantly more students rated this experiment as requiring less effort and being less difficult. Moreover, students' mathematics performance was not affected by the procedure. Experiment II strengthened the internal validity by showing that students did not prefer the experimental assignment because it contained more target problems. Experiment III showed that the interspersing procedure was not powerful enough to extend findings beyond the 20% level (i.e., 40 and 60% more conditions). Results showed how the interspersing procedure could be used to encourage students to choose to do more target computation tasks. Discussion focuses on the applied value of the interspersing procedure and plausible causal mechanisms that may account for current and past findings related to student choice and interspersing brief tasks.     

The Price of Non-reductive Moral Realism

Non-reductive moral realism is the view that there are moral properties which cannot be reduced to natural properties. If moral properties exist, it is plausible that they strongly supervene on non-moral properties- more specifically, on mental, social, and biological properties. There may also be good reasons for thinking that moral properties are irreducible. However, strong supervenience and irreducibility seem incompatible. Strong supervenience entails that there is an enormous number of modal truths (specifically, truths about exactly which non-moral properties necessitate which moral properties); and all these modal truths must be explained. If these modal truths can all be explained, then it must be a fundamental truth about the essence of each moral property that the moral property is necessarily equivalent to some property that can be specified purely in mental, social and biological terms; and this fundamental truth appears to be a reduction of the moral property in question. The best way to resist this argument is by resorting to the claim that mental and social properties are not, strictly speaking, natural properties, but are instead properties that can only be analysed in partly normative terms. Acceptance of that claim is the price of non-reductive moral realism.     

COMPARISON OF ESTABLISHED AND INNOVATIVE WEIGHT-REDUCTION TREATMENT PROCEDURES1

A central component of a commonly used weight-loss procedure developed by Stuart (1967), which emphasizes situational engineering (SE), was compared to eating behavior control (EBC), a treatment employing reinforcement of changes in eating habits. A third treatment encouraged development of individuals' own applications of a model of self-control and attempted to provide effective feedback regarding progress toward weight-loss goals. This self-initiated treatment (SI) was designed to be less directive than many behavioral treatment packages and to be more realistic about the expectations of subjects and the actual eating habits of overweight and normalweight people. Following baseline, treatment lasted six weeks and followup lasted 16 weeks. While all treatments produced weight losses, EBC surpassed SE during treatment. SI losses during treatment did not differ from SE or EBC, but SI was the only group that lost weight throughout followup, indicating the possible utility of more subtle, less directive interventions than those that have often been associated with behavioral approaches. The results of SE question the applicability to clinical procedures of the external cue hypersensitivity theory of obesity (Schachter and Rodin, 1974), to which SE is closely related.     

A company-based lottery to reduce the personal driving of employees

A company-based lottery was used to reduce the number of nonessential miles employees drove their personal cars each day and thereby save gasoline. Employees were divided into an experimental and a contrast group. The experimental design involved two conditions: (a) a baseline in which no consequences were attached to driving behavior, and (b) a month-long lottery in which the experimentals were rewarded for decreasing their percentage of average miles driven per day relative to their initial baseline average. The experimentals received an ABA order of conditions while the contrast group remained in baseline. The lottery condition consisted of four weekly lotteries and one grand drawing held at the end of the month. During the lottery condition, the experimentals reduced their average daily mileage by 11.6% relative to their initial baseline (7.85 miles per employee per day) while the contrast employees increased their average mileage by 21.2%. Both groups exceeded their initial baseline averages in the return to baseline. The study was almost cost-effective because the experimentals' gas savings ($75) was within $4 of the cost of motivating them to reduce their mileage ($79).     

Toleration and prejudice-reduction: Two ways of improving intergroup relations

While a large body of social psychological research has shed light on the nature of prejudice and how to reduce it, we argue that such work does not address situations of cultural or religious outgroup beliefs and practices that are considered incompatible with one's own. The present theoretical article contrasts a prejudice-reduction approach with a toleration-based approach to consider the differences each have with regard to the attitude object they focus upon, the perceived reasonableness of the attitude, and the behavioral consequences each may lead to. In doing so, we consider the psychological processes involved in whether the negative attitude leads to negative actions. We conclude by arguing that a toleration-based approach forms an important addition to the psychological thinking about cultural diversity and intergroup relations. Collectively, the present work makes a novel contribution to the social psychological literature by stimulating theory development and raising novel questions for empirical research.     

Helping behaviour among people who use drugs: Altruism and mutual aid in a harm reduction program

People who use drugs, and particularly people experiencing addiction, are rarely afforded the opportunity to have their voices heard when it comes to drug treatment or drug policy or even when attempting to define themselves and their life experiences. Of course, there is much more to a person than one area of their behaviour. The current study seeks to capture and understand the lived experiences of people who use drugs, with a focus on their relationships and helping behaviour. We interviewed 32 participants in a harm reduction program seeking to provide understanding beyond stigmatizing and criminalizing drug narratives, by exploring their motivation and context for helping behaviours. Grounded theory methodology was used to understand the patterns of helping behaviour, along with the contexts in which help is or is not given. We particularly focus on participants' distribution of syringes and carrying medicine to reverse overdose (naloxone). Participants shared stories of altruism and mutual aid, along with barriers and disincentives to helping others. We situate these behaviours within contrasting environments of a free harm reduction program and the competitive market system of the U.S. society. Implications for practice and public policy are discussed.     

Using a multi-user driving simulator system to explore the patterns of vehicle fleet rear-end collisions occurrence under different foggy conditions and speed limits

Vehicle fleet rear-end collisions (FRECs) are an extremely fatal type of traffic collisions on freeway and they usually occur in foggy weather. This study aimed to explore the patterns of vehicle fleet rear-end collisions occurrence under different foggy conditions and speed limits on freeway. A multi-user driving simulator system was used to conduct the experiment and the driving behavior data were collected from eight participants. The experimental results showed that as the fog density increased, the length of vehicle fleet decreased significantly, and drivers tended to keep a more stable car-following distance. The fog weather and short vehicle gap prompted drivers to react faster and brake harder in respond to the leading vehicle’s brake. In spite of the compensational behaviors, more FRECs were observed under heavy fog condition. Lowering speed limit can significantly reduce the FRECs under foggy conditions. As the speed limits reduced, drivers’ brake response time and speed variance significantly reduced. The study also found that drivers’ brake response time was negatively correlated with their positions in the fleet. Drivers in the front positions of the fleet had a longer response time than drivers in the back positions and thus were more likely to encounter collisions. The study generated a better understanding of drivers’ behavioral pattern in a vehicle fleet and the patterns of vehicle fleet rear-end collisions occurrence. The findings also shed lights on the design of driver assistance system for complex driving situations such as freeway driving under adverse weather.