Faculty Bibliography

Newcomer participation is a strong determinant of the success of online communities, particularly of open source software (OSS) development communities. Most research on newcomer participation in online communities to date has focused on internal socialization mechanisms that shape participation. No study we are aware of has looked at the role of factors external to a community itself in determining participation levels. In this study, we investigate the effect of company announcements made by OSS steward firms, events which are external to a community, on participation in newcomer communities associated with the OSS. We studied user activity in two communities, a Java newcomer forum and a MySQL newcomer forum, around two announcements that affected each community. We found evidence that company announcements had a substantial effect and participation either increased or decreased. Through analysis of secondary sources we conjecture that announcements indirectly shape participation by influencing newcomer motivation. Announcements perceived as hostile to open source values have a significant negative effect on participation, whereas announcements that were perceived as friendly either significantly increase participation or have no significant effect. Our study shows it is important to understand external factors to identify reasons for decline or growth of participation in online communities. © 2013, First Monday.

In this paper, we demonstrate that healthy adults respond differentially to the administration of force feedback and the presentation of scientific content in a virtual environment, where they interact with a low-cost haptic device. Subjects are tasked with controlling the movement of a cursor on a predefined trajectory that is superimposed on a map of New York City's Bronx Zoo. The system is characterized in terms of a suite of objective indices quantifying the subjects' dexterity in planning and generating the multijoint visuomotor tasks. We find that force feedback regulates the smoothness, accuracy, and duration of the subject's movement, whereby converging or diverging force fields influence the range of variations of the hand speed. Finally, our findings provide preliminary evidence that using educational content increases subjects' satisfaction. Improving the level of interest through the inclusion of learning elements can increase the time spent performing rehabilitation tasks and promote learning in a new context.