I'm just one data point, but that wasn't stopping me. I just couldn't think of anything worth spending everyone's time on when unsolicited. Maybe if we had broken into smaller groups for that it'd have been over the 'worth saying' threshold, and the groups could get together with whatever interesting stories/patterns they uncover?

The ideas below would probably work best for focused discussion on certain specific issues (e.g. reasons for hard takeoff, threat from nanotechnological disasters), but I think what I say below is relevant to rationalist training.

I personally often find that simple freeflowing discussion can be less than optimally effective. I often wish there was a more organized way to focus discussion to get maximum skill development. I'm afraid I'm not aware of research into refinements of general discussion designed to improve knowledge and skill acquisition.

Here are some thoughts I have.

I have found Toastmasters-style impromptu speaking practice to be an efficient and effective way to develop my ability to talk about topics. Impromptu Speaking I can imagine many ways in which such techniques could be employed for rationalist training.

Arguably some ways of doing this could put too much emphasis on rhetorical skills, but I don't think this need be true. Impromptu speaking exercises are a quick and efficient way to allow people to explore their understanding of a topic in front of an audience. With judicious use of immediate feedback, impromptu speaking could promote rationalist skill acquisition.

One advantage is that impromptu speaking makes efficient use of time. People have to think on their feet and present material fast. (For hard topics, speakers might get one or two minutes to prepare the key points of their presentation.) Public speaking practice improves understanding; even when you understand something fairly well, if you don't know it well enough to explain to someone else, you don't really understand it. (The medical school three-step program for learning how to perform a procedure seems appropriate here: See one. Do one. Teach one.)

For impromptu speaking, it is important that speakers only learn what topic they will be talking about after they volunteer; otherwise audience members will be rehearse what they will say when it is their turn to go up. I've found that one can cover quite a bit of what one understands in even two or three minutes. If done solely for the purpose of speaker skill acquisition, a designated mentor might call for the speaker to move on as soon as she demonstrates mastery of some area of concern. One key feature found in graduate school oral exams is that as soon as a student appears to demonstrate mastery in a given subject area the testers move the discussion to another subject where the student is potentially weak. It seems the same principle could work here as well.

Alternatively, If done supportingly and judiciously, audience members could interject when advanced participants are speaking and force the speaker to consider some critical point. (If this liberty is abused, each audience member might be restricted to one interjection.)

Other notes: a) There might also be a designated Socratic questioner who could potentially interpret the speaker at any given point and ask for further refinement or support of some argument. Even just watching such an interaction could be an efficient way to learn, more so than just listening to someone lecture.

b) There are no doubt other ways the feedback could best be tailored to the knowledge-level of the speaker.

c) Perhaps a list of focused readings might be put together ahead of time.

d) There might also be a running EtherPad-type commentary that would allow the speaker to be able to go back and read people's reactions and commentary on her content. If, at the end, the group desired to have a general discussion having the EtherPad could be very productive because they could start from this base of learning. (If someone knew what the best way to sync the audio with the text that would be helpful too. I know there is a feature like that for Microsoft OneNote, but that wouldn't allow for network-effect advantages.)

Another idea. What about this? People gain insights into problems with their own views when people with superior insight point out flaws, assumptions, fallacies, biases, etc. in a speaker's arguments. But if there were simply an unfocused discussion among 10 people the amount of useful feedback might be limited. As a college professor, I've found that pair work can be effective to get students practice in articulating their views. Ideally, of course, everyone could pair up with someone who sees things they are missing. Here's an idea: people first estimate their degree of knowledge about a topic. If there are ten people, someone volunteers for 10 (the highest), then people successively volunteer for 9, 8, 7, 6, and so on. After a topic is presented (and feedback is given to an impromptu speaker), people could sit in a circle in an ordered hierarchy of mentors for that topic. A facilitator could encourage all the organizational issues to take place rapidly. First, the evens turn to their right and discuss for two minutes. In this sempai-kohai relationship, first the kohai (junior member) gives his understanding of the issue, then, for each point, if the sempai has something constructive to offer, he voices it; if not, they move on to the next point. After a period of two or three minutes, the evens then turn to the left. That way, everyone would have the opportunity for focused one-on-one interaction with someone who is potentially more (and less) knowledgeable than themselves. (#10 wouldn't of course. Perhaps talking #1 could help him to have dramatic gains in understanding though.)

I can imagine different ways the above ranked ring arrangement could be used in combination with the impromptu speaking method. Perhaps, people would only give impromptu talks on one of the topics that they are generally confident about. Then the pair work discussion would commence (potentially after some form of feedback to the impromptu speaker).

"Super origin" means the story of the origin of a superhero. (Had to google for that.)