Potentiation and overshadowing between landmarks and environmental geometric cues

Rats were required in three experiments to find one of two submerged platforms that were situated in the same pair of diagonally opposite corners of a rectangular grey swimming pool. The experimental groups were trained with landmarks, comprising A4 cards attached to the walls, located in the corners containing the platforms. For the control groups, the landmarks were situated in the corners containing the platforms for half of the trials, and in the other corners for the remaining trials. Learning about the positions of the platforms with reference to the shape of the pool was overshadowed in the experimental groups when the landmarks were white, and enhanced when the landmarks were black. A fourth experiment assessed whether geometric cues influenced the control acquired by the landmarks. As in the previous experiments, the presence of the geometric cues overshadowed learning about the landmarks when they were white, but enhanced learning when the landmarks were black.     

The role of reduced frequency of knowledge of results during constant practice

Two experiments were conducted to further examine the effects of reduced knowledge of results (KR) frequency on the learning of motor skills during constant practice. In Experiment 1, participants in five KR conditions (100% KR, 50% KR-fade, 50% KR-reverse fade, 50% KR-alternative, and 50% KR-random) practiced a movement timing task. In Experiment 2, participants in two KR conditions (100% KR and 50% KR-fade) practiced a waveform reproduction task. The results of both experiments failed to indicate that reduced KR frequency was more effective in promoting learning than the 100% KR conditions. The present study adds to the increasing number of experiments that do not find a benefit of reduced KR frequency on learning in constant practice.     

Four-year changes in college athletes' ethical value choices in sports situations.

Positive values for fairness in competition are supposed to undergird the behavior of athletes engaged in sport. Whether athletes' values actually develop over 4 years in a college that emphasizes character development is the focus of this study. Athletes' (N = 631) use of deontological ethics (Hahm, Beller & Stoll, 1989) in 21 sports value dilemmas were evaluated. At entrance, as well as near graduation, intercollegiate athletes' value scores were lower than intramural athletes' scores. Both groups' scores declined while they were in college. Individual-sport athletes had higher scores than team-sport athletes but manifested a greater decline over 4 years. The findings are consistent with other studies that show decreases in "sportsmanship orientation" and an increase in "professional" attitudes associated with participation in sport.     

The Adoption of the Compact Disk Player: An Event History Analysis for the Netherlands

The compact disk (CD) player was one of the major audio innovations of the 1980s in the Netherlands. For studies of the temporal and social diffusion pattern of the CD player and the compact disks, both cultural and economic theories about innovations and music consumption are available. In this paper, these theories are combined in six working hypotheses concerning earlier adoption. The empirical analysis includes both time-invariant and time-varying variables and consumer characteristics. Event history analysis, the technique used in this article, enables one to incorporate these kinds of variables simultaneously in a dynamic model. Compared with the diffusion models usually employed by means of longitudinal analysis, event history analysis is a significant improvement in studying the development of the CD market in the Netherlands.     

Digital information evolution: the AIDS Library experience

The AIDS Library evolved out of consumer health activism in response to the need for the latest HIV information, materials, and technology. In 1998, staff implemented a microcomputer-based integrated automated library system with Web publishing capability to link catalogs, databases of Philadelphia regional services, online publications, and fact sheets. The Web site, , became "live" December 1, 1998. History leading to its development and future plans are presented.     

A medical journal's beta site: experimentation at NEJM

When continuous development becomes the norm on the social web, finding a way to put forward new development ideas to your audience and get their feedback at an early stage is the natural result. This article discusses how one major medical journal created a ‘beta’ site to support new online development and gather user feedback, speeding development initiatives and creating intrinsic value in the experimental environment. The goals of the site, organization of the teams, and practical and brand benefits are discussed.