ALTERING SHOPPERS' SUPERMARKET PURCHASES TO FIT NUTRITIONAL GUIDELINES: AN INTERACTIVE INFORMATION SYSTEM

This study reports the results of one effort to help supermarket shoppers alter food purchases to make purchases (and meals) that are lower in fat and higher in fiber. A prototype interactive information system using instructional video programs, feedback on purchases with specific goals for change, weekly programs, and the ability to track user interactions and intended purchases was evaluated. The major dependent measure was users' actual food purchases as derived from participants' highly detailed supermarket receipts. After a 5- to 7-week baseline phase, participants were randomly assigned to an experimental or control condition for the 7- to 8-week intervention phase. A follow-up phase began 5 to 8 weeks after participants completed the intervention and discontinued use of the system. The results indicated that experimental participants, when compared to control participants, decreased high fat purchases and increased high fiber purchases during intervention, with evidence for some maintenance of effect in follow-up. Plans for increasing the use and impact of the system are discussed.     

An experimental evaluation of a prototype public access nutrition information system for supermarkets

Located the Nutrition for a Lifetime System (NLS-1), a prototype interactive information system, in a large supermarket to help users decrease high-fat food purchases and increase high-fiber food purchases. Study participants were randomly assigned to control (n = 23; used the NLS-1 to enter food purchases only) or experimental (n = 26; viewed videodisc instructional programs, received prompts, made commitments, received feedback from the NLS-1) conditions. According to data entered in the NLS-1 and actual food shopping receipts, experimental participants significantly reduced higher fat purchases. Increases in higher fiber purchases favored the experimental group but were not significant.     

Presence of administrators differentially impacts eyewitness discriminability for same- and other-race identifications

Best practice guidelines recommend that eyewitness lineup administrators be blind to a suspect's identity, but no research has investigated whether the mere presence of a lineup administrator impacts eyewitness identification decisions. Informed by social facilitation theory, we predicted that the presence of an audience would differentially impact identification accuracy for same- and other-race identifications. Participants (N = 191) viewed same- and other-race lineups either with an audience or alone. Although the presence of an audience did not directly impact identification accuracy, significant indirect effects indicated that the audience provoked evaluation apprehension which hindered other-race identification accuracy and improved same-race identification accuracy. We suggest that using double-blind lineup procedures may not sufficiently protect eyewitness identification accuracy when making other-race lineup decisions in the presence of others.     

PyEPL: A cross-platform experiment-programming library

PyEPL (the Python Experiment-Programming Library) is a Python library which allows cross-platform and object-oriented coding of behavioral experiments. It provides functions for displaying text and images onscreen, as well as playing and recording sound, and is capable of rendering 3-D virtual environments forspatial-navigation tasks. It is currently tested for Mac OS X and Linux. It interfaces with Activewire USB cards (on Mac OS X) and the parallel port (on Linux) for synchronization of experimental events with physiological recordings. In this article, we first present two sample programs which illustrate core PyEPL features. The examples demonstrate visual stimulus presentation, keyboard input, and simulation and exploration of a simple 3-D environment. We then describe the components and strategies used in implementing PyEPL.     

Principles of Religious Prosociality: A Review and Reformulation

Historically, religion and religious belief have often been credited as the source of human morality. But what have been the real effects of religion on prosocial behavior? A review of the psychological literature reveals a complex relation between religious belief and moral action: leading to greater prosocial behavior in some contexts but not in others, and in some cases actually increasing antisocial behavior. In addition, different forms of religious belief are associated with different styles of co-operation. This body of evidence paints a somewhat messy picture of religious prosociality; however, recent examinations of the cognitive mechanisms of belief help to resolve apparent inconsistencies. In this article, we review evidence of two separate sources of religious prosociality: a religious principle associated with the protection of the religious group, and a supernatural principle associated with the belief in God, or other supernatural agents. These two principles emphasize different prosocial goals, and so have different effects on prosocial behavior depending on the target and context. A re-examination of the literature illustrates the independent influences of religious and supernatural principles on moral action.     

The effectiveness of short-format refutational fact-checks

Fact-checking has become an important feature of the modern media landscape. However, it is unclear what the most effective format of fact-checks is. Some have argued that simple retractions that repeat a false claim and tag it as false may backfire because they boost the claim's familiarity. More detailed refutations may provide a more promising approach, but may not be feasible under the severe space constraints associated with social-media communication. In two experiments, we tested whether (1) simple ‘false-tag’ retractions can indeed be ineffective or harmful; and (2) short-format (140-character) refutations are more effective than simple retractions. Regarding (1), simple retractions reduced belief in false claims, and we found no evidence for a familiarity-driven backfire effect. Regarding (2), short-format refutations were found to be more effective than simple retractions after a 1-week delay but not a one-day delay. At both delays, however, they were associated with reduced misinformation-congruent reasoning.     

Grain Size and Parameter Recovery with TIMSS and the General Diagnostic Model

The purpose of this study was to explore the degree of grain size of the attributes and the sample sizes that can support accurate parameter recovery with the General Diagnostic Model (GDM) for a large-scale international assessment. In this resampling study, bootstrap samples were obtained from the 2003 Grade 8 TIMSS in Mathematics at varying sample sizes from 500 to 4000 and grain sizes of the attributes from a unidimensional model to one with ten attributes. The results showed that the eight-attribute model was the one most consistently identified as best fitting. Parameter estimation for more than ten attributes and samples less than 500 failed. Furthermore, the precision of item parameter recovery decreased as the number of attributes measured by an item increased and sample size decreased. On the other hand, the distributions of latent classes were relatively stable across all models and sample sizes.     

‘Animals run about the world in all sorts of paths’: varieties of indeterminism

Synthese - In her seminal essay ‘Causality and Determination’, Elizabeth Anscombe very decidedly announced that “physical indeterminism” is “indispensable if we are to...