A number of studies have shown that students are often more willing to participate in educational conversations online than in the classroom. However, other studies have shown that online environments have poor student participation Why is this the case? What causes participation to vary from one environment to another? To explore these phenomena, we borrow a concept from social psychology, the bystander effect, which explains why individuals are less likely to helpinanemergencyifothersarepresent. Although the bystander effect specifically applies to helping behavior in emergency situations, we use this construct as a lens through which to view nonemergency situations such as educational environments. The bystander effect has 4 key components: self-awareness, social cues, blocking mechanisms, and diffuse responsibility. Focusing on these mechanisms can help us more fully characterize participation patterns observed in different educational environments and leverage this knowledge in the design of such systems. We present a case study of two students in both classroom and online French learning environments and show how the psychological mechanisms of the bystander effect help us understand observed behavioral changes. Any dialog—large or small, written or oral, scientific or casual—involves two well-defined roles: speaker and listener. In productive discourse, participants must play each of these roles at some point. For a speaker to speak, there must be an audience; for a discussion to continue, the audience must respond. Authors from many aspects of academia have attempted to define conversation and discussion in many ways, but these two features remain consistent. Ong (1982, p. 176) wrote: Correspondence and requests for reprints should be sent to James M. Hudson, College of Computing,

What is the role of collaborative tools in the context of open source engineering design innovation? In this paper, I describe ThinkCycle, an online platform that supports open collaborative design towards sustainable products. It has been used in the context of studio design courses taught at MIT. Usage patterns show several forms of intermittent online interaction but a lower level of content postings. Early results from an ongoing study suggest that while students find the online tools useful for sharing, documenting and problem solving, many perceive them as complex and an added overhead in the design process. To be more useful such collaborative systems must facilitate asynchronous lightweight interaction using existing modes of communication and design. Peer-review by external stakeholders and domain experts, not co-located with design teams, provide incentives for online collaboration.