Edit: Let's save the updating activity below for another night or for next month, when Aubrey de Grey isn't speaking.

We decided that we'd take it in turns to prepare activities for the practical rationality meetups, and I volunteered for this meetup.

Here's the plan. I have a bunch of trivia questions with numerical answers. For each question: Everyone records either 50% or 90% confidence intervals. Open discussion. Everyone may alter their intervals. Record initial and updated calibration. The aim is to test our calibration (is it true that approximately half your answers lie within your 50% confidence intervals?), ability to update (are your post-discussion guesses better?), and ability to efficiently persuade a group about something you are relatively certain about.

I propose we do both the initial estimation and discussion under moderate time pressure (i) because when you need to update in real life you often don't have much time, and (ii) so the whole thing doesn't take too long. We'll have to work out exactly how much time that should be but let's start with say 30 seconds to write down intervals and 1 min for discussion.

I'll reveal each answer immediately after and we can then take as long as we need to discuss how we're doing, so hopefully we get better as we go along. We'll be able to measure this, so at the end of the night we'll have data that will tell us if the activity was useful or not.

Suggestions are welcome.