CPSC 689/602--Spring 1997
Computer-Supported Cooperative Work
Title: Primitives For Programming Multi User Interfaces
Authors: Prasun Dewan And Rajiv Choudhary
Citation: UIST, November 3-11, 1991
Reprinted in: Baecker, R.M., Readings in Groupware and Computer-Supported Cooperative Work
1993, pp. 681-690
This paper discusses the design of a set of primitives for programming multi user interfaces by extending a set of existing high level primitives for programming single user interfaces. These primitives allow single user applications to be gradually changed to multi user applications.
Implementing a multi user interface is much more difficult than a single user interface since it involves the making and breaking of a connection.
Shared screens and windows greatly increase the power of interactive systems and they can be made to be collaboration transparent. However such an approach used has two related limitations.
Applications cannot tailor the collaboration to their needs.
It is not possible to add to these systems several useful high level primitives for tailoring the collaboration.
Suite primitives are built around the abstraction of
The Suite Primitives are divided into
Creation/Deletion Calls, Attribute Setting/Retrieving Calls, Value Setting/Retrieving Calls and Message Call.
- Active Variables : an application data structure displayed to the user that can be updated by the new values.
- Attributes : an interaction property of an active variable
- Value Group : a group of related active values that stored attributes shared by these values.
The Suite primitives can be applied to the other systems as well such as the conventional Pascal programming languages which offer the synchronous constructs such as Pascal read and write constructs for user interfaces.
This system are more incorporated to check whether each of the system is not hogging up the resources all to itself.
Although there was an intersting question posed in the class as the fact that the system is called as
high level primitives which itself contradict each other. But the author by saying primitives
means that they are a part of a toolkit and since each of them are a seperate high level entity
in its own they can be considered as high level primitives.
Report prepared by: Kushal M Agrawal Email:
Discussion date: March 24, 1997
Report date: March 26, 1997