Specialized Research Prototypes for a Collaborative Authoring

A number of research systems address group authoring of documents. Some focus on DBMS issues--versioning and concurrency. Others focus on network performance, still others the processes of writing, editing, revising and annotating of documents. These systems may primarily concern on different types of documents and structures, such as unstructured document, structured document and hypermedia. The followings are examples of available research prototypes.

PREP [11,10,12] supports collaborative writing in an asynchronous mode. PREP provides ``columns'', which show the text of the document side by side with an outline, and annotations. Versioning is supported and multi-level diff-ing is available.

GroupKit [64,46] provides shared data structures, flexible session management, remote procedure calls, concurrency controls and multi-user shared interfaces. GroupKit is a full-featured, flexible system that is more a collaboration support system than an authoring system.

SEPIA [31] supports synchronous and asynchronous cooperative hypermedia authoring. To deal with the issue of writing processes, different processes are mapped to different activity spaces. Hypertext objects are atomic nodes, composite nodes and links. Navigational tools are supplied during document creation. Other features include group awareness tools, version control, multimedia, and conferencing.

SASSE [62] supports both synchronous and asynchronous writing. The system supports individual and group writing, and other activities such as brainstorming, outlining, and reviewing. It also supports version and change control. Visual tools have been incorporated into the interface that support synchronous awareness. Documents in SASSE are plain text and a single document is the focus of a group.

Amaya and Alliance are tools being developed by The W3C, through INRIA, to browse and edit web documents where the edited documents are maintained at their original locations. Amaya [71] is an active web client which not only allows remote authoring but also provides a structured approach to web documents. Alliance [3] is an integrated collaborative authoring environment that maintains shared documents as if they were a private document.

BSCW [58] system provides facilities for collaboration over the Internet, based on the shared workspace metaphor, or an object store for group work. With its collaboration-awareness functionality, users can know of collaborative activities that happen in the workspace. Users can access to a BSCW shared workspace with web browsers and can put documents from a client machine to a BSCW. The BSCW supports distributed authoring of HTML pages by allowing documents to be published on a BCSW workspace via PUT mechanisms provided in some web browsers/editors, such as Netscape Navigator Gold or America Online AOLpress. In addition, the BSCW system provides other functionalities necessary for collaboratively distributed authoring.

CASCADE [67,70] is an environment that allows groups of people to work together writing, revising, commenting, and discussing documents. It provides four kinds of supports for collaborative authoring: augmentation, visualization, information utilization, and substitution. Navigational tools are supplied for navigation through the CASCADE document space. CASCADE is currently optimized for asynchronous commenting and document reviewing processes of a large structured document space. There are also available synchronous tools used to support collaborative activities.

Without suggesting that CASCADE is superior to any of the other research prototypes described above, our familarity with this collaborative authoring system allows us to provide some extensive detail in Appendix D. We believe this description is illustrative of the kinds of functionality that may be expected in systems specifically designed to support the creation and modification of documents by groups asynchronously over networks. It is our belief that the functionality that will be designed into these systems is significantly different from our experience with browsers to warrant explication by example.