The Discussion Cylinder

What the model assumes

• This is a simulation. No real classes or student data went into it, and its numbers aren't findings.
• The four online discussions run on one engine, and only the rules change.
• A student's balloon loses half its size about every 1.1 days. The bigger it is, the more likely they are to come back, and the more they do when they return.
• We assumed a reply pulls someone back eight times more strongly when it notifies them, as in the video loop, than when it doesn't, as in Open Discussion and 1 post + 2. Grades in Submission use the strong pull too.
• Trust decides how many students volunteer online. The Trust level slider sets where it starts, and it falls as the group grows and as more people stay silent, so a quiet room gets quieter.
• With nothing asking them to, very few people contribute. Requirements and notifications are what bring in the rest, which is why the video loop sits so far above Open Discussion.
• Students who don't volunteer are lurkers. They still read and come back, but they only do what's required.
• Seeing and hearing each other builds trust, so the video loop gets a lift. The size of that lift is our assumption.
• In the video loop, each student who volunteers has a reply habit from a bell curve centered on 4.5 and kept between 2 and 7. That range is a judgment call.
• Recording takes more effort than typing, so reactions are the rarest reply, at about 15%. Mentions usually reach 2 people.
• In a live class, three to five students take most of the turns at any class size, and the instructor speaks between each exchange.
• Breakout rooms run from minute 8 to minute 36, with rooms of about four. Rooms then report back one at a time until class ends, so in a large class some don't get a turn.
• At the party, clusters average about four people. A cluster splits, merges, or trades a person at irregular moments, every couple of minutes in a class of 12, and people leave one at a time at their own pace.
• Trust only affects the online discussions here. The live discussions are set by the floor, and the instructor's effort stays fixed at any class size.
• The online discussions run over 10 days and the live ones over 50 minutes, so compare their shapes and not their lengths.
• Visits in the online discussions are drawn longer than real ones so they can be seen.