Saul Greenberg

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Supporting awareness of others is an idea that holds promise forimproving the usability of real-time distributed groupware.However, there is little principled information available aboutawareness that can be used by groupware designers. In thisarticle, we develop a descriptive theory of awareness for thepurpose of aiding groupware design, focusing on one(More)
Physical widgets or <i>phidgets</i> are to physical user interfaces what widgets are to graphical user interfaces. Similar to widgets, phidgets abstract and package input and output devices: they hide implementation and construction details, they expose functionality through a well-defined API, and they have an (optional) on-screen interactive interface for(More)
We report on users’ revisitation patterns to World Wide Web (web) pages, and use the results to lay an empirical foundation for the design of history mechanisms in web browsers. Through history, a user can return quickly to a previously visited page, possibly reducing the cognitive and physical overhead required to navigate to it from scratch. We analysed 6(More)
This article presents an overview of GroupKit, a groupware toolkit that lets developers build applications for synchronous and distributed computer-based conferencing. GroupKit was constructed from our belief that programming groupware should be only slightly harder than building functionally similar single-user systems. We have been able to significantly(More)
This paper exposes the concurrency control problem in groupware when it is implemented as a distributed system. Traditional concurrency control methods cannot be applied directly to groupware because system interactions include people as well as computers. Methods, such as locking, serialization, and their degree of optimism, are shown to have quite(More)
Users of synchronous groupware systems act boti as individual and as members of a group, and designers must try to support both roles. However, the requirements of individuals and groups often cofic$ forcing designers to support one at the expense of the other. me tradeoff is particularly evident in the design of interaction @hniques for shared workspaces.(More)
The Notification Collage (NC) is a groupware system where distributed and co-located colleagues comprising a small community post media elements onto a real-time collaborative surface that all members can see. Akin to collages of information found on public bulletin boards, NC randomly places incoming elements onto this surface. People can post assorted(More)