Document Centered Discussion

Pattern number within this pattern set: 
Todd Davies
Stanford University
Benjamin Newman
Stanford University
Brendan O'Connor
Stanford University

Supporting group interaction around a shared document is challenging for designers of two-dimensional interfaces and asynchronous, text-based groupware. The need to deliberate (collaborate, make decisions, or make comments) around documents appears to be one of the main reasons why groups that could otherwise interact virtually and asynchronously via the Internet choose to meet synchronously, either in person or online, often in a richer environment than text-only (e.g. including audio, video, and/or a 3-D environment).

When some or all stakeholders are unable to participate in synchronous meetings, distributed asynchronous interaction offers many advantages to groups deliberating about documents: more time for reflection, revision, and information seeking (cf. Holland and Stornetta, 1992); the ability to accommodate people's conflicting schedules; flexible interaction modes through conversion of text to/from speech (e.g. for disabled or less literate users); the easier access, storage, and search afforded by digital archives; and (Price and Cappela, 2002) the empowerment of those who are at a disadvantage when participation involves speaking in a live group. But mapping in-person meetings onto an asynchronous interaction through distributed 2-D text displays entails several types of lost richness, including nonverbal grounding cues (Clark and Brennan, 1991), spatial depth, the natural use of separate perceptual modalities for document (visual) and discussion (auditory); and the use of a shared temporal progression to guide attention.


In our usage, a document can be in any format, including images, audio and video, but our primary focus here is on digital documents in which most of the information is in text. Discussion that takes place around a document consists of comments that pertain either to the document as a whole or to some part of it. The document may be either fixed or evolving as the discussion around it proceeds, but the document assumes an elevated status over the comments made about it, e.g. because it has been chosen for careful discussion, or because its final version will have governing consequences or will represent the outcome of a collaboration. In the latter cases, the group must somehow reach a decision relating to the document (e.g. to adopt it).


[NOTE: This pattern focuses on interfaces for visually-abled users. Adapting the analysis presented here for visually impaired users might be possible, but our feeling is that that will require quite a different approach, one we hope to investigate in the future.]

The projection of a 3-D, multi-modality, co-located, synchronous deliberation experience onto a 2-D, primarily visual, distributed asynchronous interaction requires essential aspects of face-to-face deliberation to be remapped onto a screen interface. The needed mappings can be judged according to two broad goals:

  • Visible relationships. Relationships between comments and the texts they reference, between different comments, and between group members and the document and discussion, should be as visible as possible.
  • Distinguishable boundaries. Separations between contextually related and unrelated text and comments and between individual authors of documents and comments should be as distinguishable as possible.

Let us consider each of these goals in more detail.

Visible Relationships

Exhibiting relationships between the components of document-centered deliberation (document, comments, and participants) implies a number of refinements of this goal. First, the document text that is the target of deliberation should be co-visible (displayed simultaneously) with comments around it, and the identities of comment authors and document text, when relevant, should also be co-visible with their output. Second, the referencing relationship between a comment and its target text should be visible, i.e. the interface should incorporate ostensive pointing (meaning that a pointing relationship is displayed on the screen rather than being enacted through a peripheral device) and in-text placement of comments. Third, response relationships between comments should be visible through threading. And fourth, the reactions of deliberation participants should be visible through polling and decision features.

Distinguishable Boundaries

Visible relationships can be inadequate, as anyone would know who has used a map with ambiguous place labelings. The interface should also mark boundaries between text that is and is not the reference target of a comment, e.g. though text highlighting. Text authored by different people at different times should be distinguishable through textual boundaries. The topic of a text should be able to be viewed separately from its main body through headers. And obsolete comments (i.e. made on a previous version) should be recognizable through pertinence markers.


Applying the principles of relationship visibility and boundary distinguishability in an integrated way puts online deliberators at less of a disadvantage relative to their face-to-face counterparts. The Deme environment for online deliberation (Davies et al., forthcoming) is a tool for document-centered discussion, polling and decision making that incorporates all of the elements derived above in a dynamically updating (no-page-reload) interface.

The summary image shows the most recent design of the meeting area viewer in Deme. The shaded-in header of a comment in the discussion view pane on the right points to a shaded-in comment reference in the text of a document shown in the item view pane on the left.

Deme provides co-visibility between document and comments through an optional split-screen view. In-text comment references are transiently pointed to (the dotted-line arrow goes away as soon as the user scrolls) when clicked on, and comments are displayed in the context of hierarchical threads. Members can vote on documents under a variety of decision rules. Boundaries are provided through highlighting, text boundaries, headers, and a versioning system that remembers when comments become obsolete and marks them as such. The design takes advantage of no-page-reload web server calls to provide dynamic relationship visibility and boundary distinguishability.

Pattern status: 
Aaron Tam
Stanford University