Selected Planned Agents

Below is the reviews of the general agents that are envisioned for CASCADE--Document Agents, Navigation Agents, Writing Assistants, Management Agents, and Personal Preference Agents.

Document Structuring Agents

The document agents will be built with three basic assumptions in mind. First, the underlying electronic document will be SGML-compliant--i.e. it will be rigorously structured and controlled from a logical point of view. Second, it will make use of a system for linking document components in a controlled hypertext web that adds integrity assurance to URL and Hytime standards. CASCADE will build on the widely used URL approach adding the structure and control suggested by the Dexter Hypertext Model. Third, agents will employ message passing.

The current document space in CASCADE reflects the underlying unix file system. This will be replaced with an SGML repository residing in the DBMS that views the document as a logical structure consistent with both SGML and the user's mental model of the document and comments. Within the structure the user should be able to seamlessly view the entire document even though each section may be under the control of a different individual or group.

Research indicates the importance of the representation of text. Comments and revisions need to be associated with the appropriate portion of text. There is a need to facilitate commenting 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. 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 revisers is required. This concept also relates to generations of the same documents and management of those previous versions. Access to the current, as well as prior, versions of each document section will be supported. Document space construction agents will be responsible for both the logical structuring of the entity as well as the physical creation of the structure. In addition, the Document Space Agent will be responsible for distribution of the components in order to achieve the goal of document immediacy and ubiquity.

While CASCADE will support and encourage electronic documents that have no linear form, there is a clear need for the creation of paper and electronic copies of documents that have a ``normal form''. This will be the responsibility of the Linear Document Construction Agent. This will require that the agent understand how and when links are to be traversed, and how the resulting composite document should be processed for presentation.

CASCADE provides a number of facilities for inserting, reviewing, and reporting on comments which will be presented in the next section.

Navigation and Browsing Agents

The prototype browsing tool currently provides a two-dimensional overview of the physical document space. Docuverse represents a large document space by selecting only one or two attributes of the documents in the space. The browser is a tree-based structural display of part of the document. It shows individual document components and the links between them. Also the landmark and preview tools are used to aid navigation in CASCADE. More details will be presented in the next section.

A graphical directory tree makes it easy to find the desired document and its sub-components. Usability studies will be required to determine the best graphical representation. The navigation function will map additional data to the visual structure in accord with the general rules set out by Spring [6]. Icon color, size, shape, and intensity can be used to display various information about the node. Finally, a lens feature can be implemented to allow for component preview. A document viewer is an integral part of the navigation mechanisms. Whenever a document node is accessed, the document contents become visible along with its hypertext links. Given the proper permissions, a document may be directly edited at this point but it is anticipated that only minor changes will be performed this way. The viewer will mainly be used to read and navigate the hypertext document and to embed comment or reference links directly into the text.

Writing Assistants

Every document is written in accord with a set of goals and constraints; it is important for the author to be mindful of these. Engelbart and Lehtman [] discuss the notion of an on-line handbook which contains pertinent information for a given project. Writers could access a listing of relevant information about a particular document.(This informational object mechanism could be sensitive to the specific document and present information accordingly.) This suggests a document information agent with information about audience, tone, style, deadline, key words, words and phrases to be avoided, sample formats, etc. which could be invoked as needed by the writer. Writers might request that the system check their work against a designated standard. The writer could select the topic of choice, view his/her document and the explanation. We believe that providing constraint management for style, content, and format concerns will improve the quality of the document and reduce the amount of time needed to complete the document. The following questions will need to be answered.

1. What is the most effective way to present this information to the users?

2. Given that authors will find the notion of a ``reminder'' window useful, what document information should be maintained?

3. Will all authors or will only the primary author use them (find them useful)?

4. How will system checking of the work of the authors affect the quality of the product?

5. Will these features result in earlier draft versions because authors know that `checker' features are available?

6. What writers workbench kinds of features will be most used?

Management Agents

There are any number of decisions that will need to be made by the individual or team with overall responsibility for the group effort. These include such mundane issues as setting up versioning parameters, checking system usage, creating or changing access rights, etc. At a meta level, some individuals will want administrative agents that do all the work. Others will want administrative agents that only execute explicit instructions. Below we provide a sample of the kinds of agent functionality that will be explored in this class.

1. provide for version/revision control -- number of versions to keep, when to establish major version points, etc.

2. assignment of components to individuals and vice versa.

3. reports on attempted security violations or complaints regarding access.

4. locking/unlocking of components as they are completed or opened for change.

5. check-out and check-in of documents as they are worked on

6. collection of ``garbage'' for audit trails. For example, as components are completed or as comments are marked as ``satisfied'', ``outstanding'', or ``irrelevant'', keep track of what is done.

Time management is another concern in collaboration. Deadlines could be brought to the writers attention in a variety of ways--e.g. messages when a deadline is approaching, Changing color of the document's border or icon, etc. To develop a time management module, we need to know the types of reminders are most effective and least offensive to users, which visual cues best indicate priority, etc.

Personal Preference Agents

In addition to `look and feel' preferences such as colors, fonts, window decorations, sizes and bitmaps, the personal preference agent will handle such things as:

1. Preferences for views and filters

2. Preferences for starting location i.e. ``home'' versus ``last location''

3. Writing/commenting preferences such as signature files for comments and mail, default name and type for comment labels, etc.

4. Display/browsing preferences such as which links to display, how to annotate them, i.e. by date, by username, etc.