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4.2 Social mechanisms in communication and collaboration 127

Figure 4.10 A screen dump of Portholes, showing low resolution monochrome images from
offices in the US and UK PARC sites. (Permission from Xerox Research Centre, Europe)

set-up suggested that having access to such information led to a shared sense of
community.
The emphasis in the design of these early awareness systems was largely on
supporting peripheral monitoring, allowing people to see each other and their
progress. Dourish and Bellotti (1992) refer to this as shared feedback. More recent
distributed awareness systems provide a different kind of awareness information.
Rather than place the onus on participants to find out about each other, they have
been designed to allow users to notify each other about specific kinds of events.
Thus, there is less emphasis on monitoring and being monitored and more on ex-
plicitly letting others know about things. Notification mechanisms are also used to
provide information about the status of shared objects and the progress of collabo-
rative tasks.
Hence, there has been a shift towards supporting a collective "stream of con-
sciousness" that people can attend to when they want to, and likewise provide in-
formation for when they want to. An example of a distributed awareness system is
Elvin, developed at the University of Queensland (Segall and Arnold, 1997), which
provides a range of client services. A highly successful client is Tickertape, which is
a lightweight instant messaging system, showing small color-coded messages that
scroll from right to left across the screen (Fitzpatrick et a]., 1999). It has been most
useful as a "chat" and local organizing tool, allowing people in different locations
to effortlessly send brief messages and requests to the public tickertape display (see
Figure 4.11). It has been used for a range of functions, including organizing shared