The challenge of devising an interaction structure for the meeting had two sides: First, the need to enable orderly, yet relatively unconstrained conversations, through which knowledge and information about the proposals could be built; second, the need to produce a coherent textbase which would index each comment according to its type of move in a conversation. The messages posted to the meeting were imagined as both pieces of ongoing conversations about particular proposals and parts of a self-extending, distributed hypertext, contributed by multiple sources, including NPR. However conventional messages threaders, such as subject, target ("in reply to"), submission time, were deemed insufficient to structure or represent a set of messages as a sequence of conversational or rhetorical.
Indexing the intentions of the moves is important: First, on the view that conversations are composed of interlocking moves or speech acts, on-line communications are problematic, because they have fewer inflection, non-verbal and setting cues which speakers in face-to-face communications exploit to make and recognize speech acts, their intentions, and the expected responses. When the move types of posted comments are indicated, a user can know what types are appropriate responses to a target she has chosen, and by identifying the type of her comment, she can indicate the type of response she expects. Second, when comments are threaded through their targets in hypertext display, the tagging clarifies the relationships between otherwise opaque texts (especially when the text itself is not displayed but only pointed at by a link), and provides an overview of the flow of intentions and expectations through the entire conversation. Finally indices are needed so for a given target, all replies of the same attitude, agreement for example, can be displayed together, retrieved together or more easily checked for redundancy.
The indices can be obtained by asking contributors to identify the types of moves they are making. This self-indexing is similar and not necessarily more inhibiting than the widespread practice of putting "smilies" and other cues into email messages to reduce their ambiguity.. Self-indexing of utterances is also a standard linguistic practice, especially when there is a probability of misinterpretation or a particular type of move is privileged, in the sense of having a priority on getting attention, e.g., "I have a question?"
We also imagined that the sequences of moves and the discussions they created would be constrained by a context sensitive discourse grammar, a set of moves and rules that restricts their possible combinations by specifying the moves that can be legally attached to each move. These rules abstract the notions of appropriateness and expectation that are associated with the move types in a sequence. Since they have institutional as well as logical bases, a grammar encapsulates a quasi normative order or a procedure employed for a social purpose, not just idealized linguistic phenomena The sequences which we thought most likely to occur and best to support on-line were multi-lateral arguments for and against the proposals. Our model of argument was influenced by modern dialectical theories, which understand argument as an ordered, interactive process whose utterances are constrained to speech acts for making and supporting claims, challenges and rebuttal.[7,9,8]. The highly restricted move sets of the dialectical argument models were attractive because they barred the flames, digressions, emotional discharges and similar failings of newsgroups. However, we anticipated that discussions constrained by that grammar would be more conflictual and address fewer possibilities than if the grammar also permitted alternatives, examples, information seeking questions and answers. Because the Open Meeting was intended to stimulate interest and accumulate information about government reinvention, the teams selected moves that could lead to consensus while permitting differences of opinion: Agreement (reason for), Disagreement (reason against), Question, Answer, (propose an) Alternative, Qualification ("yes, but"), or (report a) Promising Practice. The root document explained these types, presented a distinctive icon for each, and asked users to frame comments according to them.
The grammar for the meeting was additionally shaped by pragmatic institutional as well as logical constraints. To avoid the scent of electronic plebiscite, polling, voting and simple endorsements were not implemented. Agreements and Disagreements had to provide reasons. Because the executive summaries, the overviews based on them, the appendices and the example promising practices were approved by NPR leadership, they were in a sense above debate, at least by workers at the meeting and no comments could be attached to them. Finally, the attachment of alternatives to questions, answers or promising practices, and the attachment of anything but answer to question were considered illogical and excluded.
The discourse grammar is weakly enforced in the Open Meeting system by using it to drive the dynamic reconfiguration of input interfaces. Given the user's choice of target, the server presents an input interface which limits the choice of comment types to just those which can be "legally" attached to the target's type. Of course, this does not prevent a user from flouting the rules, by identifying a comment as a permitted move, but actually making one that is not. A common case of flouting in political meetings is the use of a turn in the question period to assert one's own position, sometimes eliciting the rebuke: "That's not a question?" In general, to prevent potentially disruptive flouting requires natural language processing capability that understands the intention of utterances -- not just recognizes forms. Absent robust natural language processing technology for this, human moderators are needed to verify that the contributor has not flouted. As noted above, moderators for the meeting did verify that Agreements and Disagreements gave reasons, but verified no other move types, because of the low potential for disruptive flouting.
The resulting virtual discussions in the Open Meeting differed from face-to-face, multi-lateral discussions in not having an inherent linearity, that is, forward movement toward conclusions. In face-to-face conversations, discourse contexts or foci of attention are successively closed to further comments and are only reopened with difficulty. A speaker might present a reason against a proposal, with the reason then becoming the context of subsequent debate among speakers. At some point, however, discussion returns from this stack to the top level and moves to another point, opening another context. There will be no backtracking to the first context, unless information or conclusions are premises that have been contradicted in the current context. In the virtual discussion on a proposal, all the contexts (and their contexts recursively) remained open to further comment, even if recent comments were in the same context. The discussion could therefore develop as a set of statement and reply sequences on different points, a long sequence elaborating one point (analogous to breadth versus depth search) or a mix of both approaches. This openness partly reflects the primary orientation of the meeting toward collecting information and building knowledge rather than moving a community toward a consensus.
Unfortunately, the outline form used on the web page to represent the links in the hypertext obscures the time dimension and possible focus or convergence in the discussion. This regime recursively indents the pointer to a comment with its move type icon under the pointer to its target, with comments at the same level listed in order of submission. As a result some comments at a deep level that were more recent than other comments at a more shallow level can higher on the page. Since all submissions are time stamped, it is trivial to present the hypertext in ways that could encourage or represent convergence, such as hiding or closing contexts that have received no comment for an arbitrary time and color coding contexts according to how recent are the last comments in each.