Paranoid Debating is a variant of The Aumann Game where one player purposefully subverts the group estimate. Similar to The Aumann Game, the activity consists of a group jointly producing a confidence interval for an unknown, but verifiable quantity, which is then scored for accuracy and calibration. One individual is designated the spokesperson, who is responsible for choosing the final estimate. However, before the activity begins, one individual is secretly assigned the role of misleading the other members. The deceiver is scored higher the worse the final estimate is.
The activity is intended to teach accurate estimate, proper agreement techniques, and recognition of deception.
A typical subject for the game might be "How much maize is produced in Mexico annually?".
Advocate variant, #1
Advocate variant, #2
Southern California Variant #1
At the February 2011 Southern California LW Meetup we tried playing the game. For questions we bought a game of Wits & Wagers (which has trivia questions with numerical answers) and looked at the cards to find questions that were about substantive topics where Fermi estimates seemed useful. The speaker/advocate was chosen on a rotating basis so that everyone gets at least one chance to play that role, and cards are dealt from a deck of playing cards to everyone else. Red cards mean you're trying to make the group deliver a bad answer. Black cards mean you're trying to make the group deliver a good answer. This makes the number of people to be suspicious of itself an unknown parameter and leads to funny outcomes and interesting coordination problems. Scoring used the experimental scoring code that is intended to assign the most credit to small error bars around high confidence correct answers.
It's really easy to ask a question that is then very difficult to answer later. For example, the question "How many miles of railroad are there in Africa?" is somewhat difficult to answer. Walking through the CIA World Fact Book one country at a time, we arrived at an answer in the range of 48,000-49,000. However, in cross-checking that information, we discovered that in Uganda, there are only 125 miles of active railroad, but 1200km listed in the Fact Book. It seems likely, therefore, that the total estimate includes some non-active miles of railroad, and is thus too high. This section is here to list good and bad questions and resources to get questions from or answer questions unusually easily. If listing an answer, please make the text of the answer white so people can use it if they want.
A not-so-trivial inconvenience to playing the game is figuring out how to score it properly.
To make this easier there is now a tentative file format for representing a game of paranoid debate and a python script for scoring games represented in this format. If you'd like to download or edit this software check out this github project. Please note that the game format and the code are very likely to evolve to remove bugs and support whatever sort of play turns out to be the most fun and/or educational.