To effectively design a system to support collaborative authoring, one must understand, not only the writing process, but also the collaboration aspect. Eason  believes that technology for collaborative authoring should support, not control and manipulate collaboration. "Computer systems to support the writing process will be of most help if they fit the writer's perception of the task and assist whichever strategy the writer chooses to adopt" . This is particularly relevant given the diverse writing strategies each author and each writing group can adopt. These different writing strategies should be supported. A particular writing style should not be forced upon the user. Further, thoughts on designing a collaborative authoring system need to focus on group writing behavior, not single authorship activities. Focusing on single writing activities will lead to a collaborative system that is inappropriate for the task .
Writing research can provide information for the design of computer systems-- how software might be developed to support a range of writing strategies [50,8]. Because writing complex, and open-ended, there is the possibility of stating meaning in a variety of ways. With multiple writers, the level of complexity increase. Too, there must be a mechanism for the writers to express ideas about the document, constraints, and strategies. Writing, therefore, includes making notes, sharing ideas, and discussion.
Research indicates the importance (to the collaborative authoring process) of the representation of text--uninstantiated as well as instantiated. Comments and revisions need to be associated with the appropriate portion of text. This enables the context of these items to be easily determined. Rimmershaw  addresses this situation by specifying that 'meta-comments' linked to related text is a means of capturing informal notes. There is a need to facilitate making meta-comments and linking these comments to specific parts of text. Also related is the display of various text items--full text, 'place-holders', and annotations. Their distinct functions imply a need to represent or display these items differently. Further, a co-author may wish to make comments or annotations on a portion of text for his/her personal use, not to be shared with the group. A mechanism for supporting this type of annotation would be useful.
The right to directly modify or alter the text is another option needed in a collaborative system. This implies that the ability to identify commentors or revisors is required. This concept also relates to generations of the same documents and management of those previous versions. Related concerns are: storage requirements, labeling conventions, guidelines for what is worth maintaining. Version management is pertinent given the cyclical nature of writing and the notion of existing text as a constraint to be managed.
Another design feature is the capability of having multiple items of interest in view at once. This reduces the cognitive processing required to remember each item not displayed. For example, a writer may need to view his/her portion of the text, the guidelines identified by the group, a sample format of a similar document, and another writer's comments. This would facilitate the communication of goals as well s the management of some constraints (such as using a "boilerplate").
In general, the system designer needs to provide an appropriate view of documents . Appropriate in the sense that it enables the writer to perform tasks related to writing with limited cognitive overload. Also associated with the document view is interface design. One issue related to interface design is determining what should be made visible when a change is made to a document. Another concern is how the system displays multiple comments related to one specific portion of a document. Also, what happens if more than one author attempts to modify (or delete) the same subsection of a document at the same time. In general, the interface design issue relates to how the document, comments, revision, deletions, discussions, and other writing activities are visually displayed. These items should be represented in such a way that there meaning is apparent or easily determined. (The topic of interface design is worthy of a separate paper. Therefore, it is not be addressed in much detail here.)
According to Ellis, Gibbs, and Rein , three elements are important in providing support for group interaction: communication, collaboration, coordination. The facility to share information is the key to collaboration. Communication refers to the capability to integrate electronic communication such as email with face-to-face and telephone communications. Coordination reduces conflicting and repetitive actions by individual team members. Dillon  believes that there is a need for better technology for collaboration, that is better communication mechanisms. These mechanisms should enable authors to contact each other and facilitate document transfer. As noted in the Beck study, much of the discussion regarding document content and structure, organization of work, and relationships between co-authors occurred during the writing of the document. Further, Ede and Lunsford  noted that of all the methods used for creating a document, most worked alone as well as with the group. Coordination is critical in this situation.
The role of technology should be to support people, but it can control or manipulate collaboration at some degree. It should allow for natural group activities. One group activity is changes in group membership. According to the studies of collaborative authoring groups, there were noticeable changes in group structure. This indicates the need for flexibility. The collaborative authoring system should support the removal and addition of group members. Also, issues concerning maintenance of contributions of the 'retired' member(s) must be addressed. These issues relate to accessibility, storage, and use of these contributions. Protection of ideas and other contributions is an important system feature. While all group members should have the capability to create full text, comments and revisions, there needs to be a mechanism for identifying the contributor. This not only provides information to the group if questions arise, it also gives credit to members for their input. Since the vision cues associated with face-to-face communication are absent, knowing who made a comment may provide more information about the tone and context of the comment. (As mentioned in the collaboration subsection, receiving credit for one's ideas was a concern for writers.)
Ideas many times come from informal, casual conversations. Some suggestions for the writing project may be provided by individuals who are not members of work group. The issue is handling critical ideas from such individuals. Also, the handling of verbally relayed comments and ideas (by group members) is a related issue.
Another group activity is the formation of sub-groups. Support for sub-groups may include sub-group only access, authoring, and communication privileges. The writing group may comprised of members from different disciplines. In such a case the notion of consistency in terminology, abbreviations, and acronyms is of utmost importance. One way of addressing this is with a word processing type feature that could search for phrases and words to be avoided. This function would alert the writer to unacceptable text items and suggest appropriate choices (such as valid abbreviations). Such features would reduce the need to remember or 'look up' such text items.
The variety of roles assigned to or assumed by group members need to be addressed system design. Too, a single member may change roles during the document creation process. There should be a means of identifying the roles of each team members and the appropriate allowable actions should be defined. (For example, the leader can access the sub-tasks of all members, while individual members have access to their particular work. However, once a version of the complete document has be made public, all members can access it to comment, revise, etc.) Along with the issues of roles, there is a need to support project management functions. Some of these functions are: task assignments, monitoring work products, and polling group members. The system need to provide for the use of a project management tool, such as critical path method (CPM).
Overall, the system needs to be flexible to support the variety of writing strategies and group organizations that are inherent in collaborative authoring. Further, the changing nature of the strategies and group structure support this concept. The system also needs mechanisms for tracking discussion, comments, and decisions.
Neuwirth et al.  identify several issues related to asynchronous collaborative authoring. Commenting is a major activity for communication within authoring groups and between readers and such groups. Collaboration supports include social interaction support among co-authors and commenters and cognitive support for co-authoring and external commenting. Fish , explores the strategy of defining social roles, such as primary author, commenter, reader, for individual collaborators to reduce coordination problems. Only a limited set of actions associated with social roles and objects is permissible. However, roles in collaborative authoring may vary in different contexts and regardless of individual social roles, some commenters  would like to rewrite the whole text instead of simply commenting the document. Writers need to be able to communicate among collaborators about plans or goals of authoring in order to get cohesive products. Communication about evolving plans and other constraints may improve quality and efficiency. Effective communication is also needed to improve comprehension about comments.
Support for cognitive aspects of collaborative writing include both individual and group authoring activities. Jotting, drawing, note-taking, gesturing, and reading are typical task-specific activities in writing. Author's ideas or planning activities may be suppressed unless the support tools provide compatible tools or procedures to those activities. Computer support should reduce cognitive load by allowing writers to see intermediate representations of documents (sketches), i.e. to see an outline in a tree-like structure, to sort items in an outline, to compare two versions of drafts, etc. Not only co-authors but also commenters require cognitive aid tools to perform activities. The commenter-author relationship is enhanced when both peers can do their tasks, such as accessing plans or comments, outlining a draft, finding main points, without much cognitive effort. One major point is that most text annotation systems employ the hypertext model so that accessing information is to follow a link from node to node. Obviously, navigation through a complex network of comments is a difficult task. Visualization tools can greatly reduce mental load while accessing comments.