Dear Area Chairs, Readers:
In addition to recommending preliminary accept/reject decisions, we had asked you to recommend submissions for either an oral or a poster format. While ACL recognises both formats as equally prestigious, but the question of what type of work is best suited for oral or poster presentation is important to discuss. Rather than write overly long instructions to you in the emailed agenda for recommending papers, we thought it would be better to blog about it instead.
As always, we appreciate your discussion in the comments, especially viewpoints in opposition to those expressed here, in part to help make the deliberation a useful source of evidence for future area chairs and PCs.
In summary: The key question is whether the paper is best suited towards a broadcast style or to a discussion style .
Oral: Broadcast connotes a one-way, directional form of dissemination, where topics and details are concrete and the audience is many at once. It’s suited for topics that attract a wide audience that are representative of the (parallel oral) track. It is better suited for papers whose main ideas can be grasped within the time limit of the presentation (for ACL, typically 15-20 minutes).
Poster: Discussion connotes a two-way conversational style, that better promotes clarification, building upon, in-depth examination among a small group of peers. It’s suited for specialised work in an area that would attract a dedicated group of scholars, and works that have technical intricacies that are better appreciated in depth or guided by the presenter.
There are separate considerations from the perspective of presenters, but these should not be considered at the programme organisation level. For presenters, these consideration include which format creates the most impact, in terms of affecting the course of future research and creating opportunities for interaction (although feel free to voice opinions on this in the comments).
 Alex Becker’s answer to an Academia StackExchange question posed by Jeromy Anglim: http://academia.stackexchange.com/questions/10902/talks-vs-poster-presentations-which-is-better-for-advertising-your-research-an