The Good Judgment Project

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The Good Judgment Project (GJP) is an organization dedicated to "harnessing the wisdom of the crowd to forecast world events". It was co-created by Philip E. Tetlock (author of Superforecasting and Expert Political Judgment), decision scientist Barbara Mellers, and Don Moore, all professors at the University of Pennsylvania.[1][2][3]

The project began as a participant in the Aggregative Contingent Estimation (ACE) program of the Intelligence Advanced Research Projects Activity (IARPA).[4][5] It then extended its crowd wisdom to commercial activities, recruiting forecasters and aggregating the predictions of the most historically accurate among them to forecast future events.[6][7] Predictions are scored using Brier scores.[8] The top forecasters in GJP are "reportedly 30% better than intelligence officers with access to actual classified information."[9]


The Good Judgment Project began in July 2011 in collaboration with the Aggregative Contingent Estimation (ACE) Program at IARPA (IARPA-ACE).[10] The first contest began in September 2011.[11] GJP was one of many entrants in the IARPA-ACE tournament, which posed around 100 to 150 questions each year on geopolitical events. The GJP research team gathered a large number of talented amateurs (rather than geopolitical subject matter experts), gave them basic tutorials on forecasting best practice and overcoming cognitive biases, and created an aggregation algorithm to combine the individual predictions of the forecasters.[5][12] GJP won both seasons of the contest, and were 35% to 72% more accurate than any other research team.[13] Starting with the summer of 2013, GJP were the only research team IARPA-ACE was still funding, and GJP participants had access to the Integrated Conflict Early Warning System.[8]


The co-leaders of the GJP include Philip Tetlock, Barbara Mellers and Don Moore.[1] The website lists a total of about 30 team members, including the co-leaders as well as David Budescu, Lyle Ungar, Jonathan Baron, and prediction-markets entrepreneur Emile Servan-Schreiber.[14] The advisory board included Daniel Kahneman, Robert Jervis, J. Scott Armstrong, Michael Mauboussin, Carl Spetzler and Justin Wolfers.[15] The study employed several thousand people as volunteer forecasters.[12] Using personality-trait tests, training methods and strategies the researchers at GJP were able to select forecasting participants with less cognitive bias than the average person; as the forecasting contest continued the researchers were able to further down select these individuals in groups of so-called superforecasters. The last season of the GJP enlisted a total of 260 superforecasters.[citation needed]


A significant amount of research has been conducted based on the Good Judgment Project by the people involved with it.[16] The results show that harnessing a blend of statistics, psychology, training and various levels of interaction between individual forecasters, consistently produced the best forecast for several years in a row.[12]

Good Judgment Inc.[edit]

A commercial spin-off of the Good Judgment Project started to operate on the web in July 2015 under the name Good Judgment Inc. Their services include forecasts on questions of general interest, custom forecasts, and training in Good Judgment's forecasting techniques.[17] Starting in September 2015, Good Judgment Inc has been running a public forecasting tournament at the Good Judgment Open site. Like the Good Judgment Project, Good Judgment Open has questions about geopolitical and financial events, although it also has questions about US politics, entertainment, and sports.[18][19]

Media coverage[edit]

GJP has repeatedly been discussed in The Economist.[11][20][21][22] GJP has also been covered in The New York Times,[3] The Washington Post,[5][23][24] and Co.Exist.[25] NPR aired a segment on The Good Judgment Project by the title "So You Think You're Smarter Than a CIA Agent", on April 2, 2014.[9] The Financial Times published an article on the GJP on September 5, 2014.[26] Washingtonian published an article that mentioned the GJP on January 8, 2015.[27] The BBC and The Washington Post published articles on the GJP respectively on January 20, 21, and 29, 2015.[28][29][30]

The Almanac of Menlo Park published a story on the GJP on January 29, 2015.[31] An article on the GJP appeared on the portal of the Philadelphia Inquirer,, on February 4, 2015.[32] The book Wiser: Getting Beyond Groupthink to Make Groups Smarter has a section detailing the involvement of the GJP in the tournament run by IARPA.[33] Psychology Today published online a short article summarizing the paper by Mellers, et al., that wraps up the main findings of the GJP.[34][35]

The project spawned a 2015 book by Tetlock and coauthored by Dan Gardner, Superforecasting - The Art and Science of Prediction, that divulges the main findings of the research conducted with the data from the GJP.[36] Co-author Gardner had already published a book in 2010, that quoted previous research by Tetlock that seeded the GJP effort.[37] A book review in the September 26, 2015, print edition of the Economist discusses the main concepts.[38] A Wall Street Journal article depicts it as: "The most important book on decision making since Daniel Kahneman’s Thinking, Fast and Slow."[39] The Harvard Business Review paired it to the book How Not to Be Wrong: The Power of Mathematical Thinking by Jordan Ellenberg.[40] On September 30, 2015, NPR aired an episode of the Colin McEnroe Show centering on the GJP and the book Superforecasting; guests on the show were Tetlock, IARPA Director Jason Matheny, and superforecaster Elaine Rich.[41]

See also[edit]


  1. ^ a b "Welcome to the Good Judgment Project". The Good Judgment Project. Retrieved May 5, 2014.
  2. ^ "Who's who in the Good Judgment Project". The Good Judgment Project. July 27, 2011. Retrieved May 5, 2014.
  3. ^ a b Brooks, David (March 21, 2013). "Forecasting Fox". New York Times. Retrieved May 5, 2014.
  4. ^ "The Project". The Good Judgment Project. Archived from the original on May 6, 2014. Retrieved May 5, 2014.
  5. ^ a b c Horowitz, Michael (November 26, 2013). "Good judgment in forecasting international affairs (and an invitation for season 3)". Washington Post. Retrieved May 5, 2014.
  6. ^ "About Superforecasting | Unprecedented Accurate & Precise Forecasting". Good Judgment. Retrieved 2022-02-17.
  7. ^ Matthews, Dylan (2022-02-16). "How can we prevent major conflicts like a Russia-Ukraine war?". Vox. Retrieved 2022-02-17.
  8. ^ a b Dickenson, Matt (November 12, 2013). "Prediction and Good Judgment: Can ICEWS Inform Forecasts?". Predictive Heuristics. Retrieved May 24, 2014.
  9. ^ a b Spiegel, Alix. "So You Think You're Smarter Than A CIA Agent". Retrieved 2014-08-18.
  10. ^ "The idea behind the Good Judgment Project". The Good Judgment Project. July 27, 2011. Archived from the original on May 6, 2014. Retrieved May 5, 2014.
  11. ^ a b "The perils of prediction: Adventures in punditry". The Economist. September 2, 2011. Retrieved May 6, 2014.
  12. ^ a b c Mellers, Barbara; Ungar, Lyle; Baron, Jonathan; Ramos, Jaime; Gurcay, Burcu; Fincher, Katrina; Scott, Sydney E.; Moore, Don; Atanasov, Pavel; Swift, Samuel A.; Murray, Terry; Stone, Eric; Tetlock, Philip E. (2014-05-01). "Psychological strategies for winning a geopolitical forecasting tournament". Psychological Science. 25 (5): 1106–1115. doi:10.1177/0956797614524255. ISSN 1467-9280. PMID 24659192. S2CID 42143367.
  13. ^ "The first championship season". Good Judgment. Retrieved 2022-02-17.
  14. ^ "Team". The Good Judgment Project. Retrieved May 5, 2014.
  15. ^ "Freakonomics". Sign Up for a Prediction Tournament. 2011-08-04.
  16. ^ Multiple Sources:
  17. ^ Brody, Liz (January 1, 2022). "Meet the Elite Team of Superforecasters Who Have Turned Future-Gazing Into a Science". Entrepreneur.
  18. ^ Gossett, Stephen (August 6, 2020). "How the Good Judgment Project's Superforecasters Use Data to Make Predictions". Retrieved 2022-06-07.
  19. ^ "Good Judgment® Open". Retrieved 2022-02-17.
  20. ^ "Monetary policy: How likely is deflation?". The Economist. September 13, 2011. Retrieved May 6, 2014.
  21. ^ "International: Who's good at forecasts? How to sort the best from the rest". The Economist. November 18, 2013. Retrieved May 6, 2014.
  22. ^ "The experts' best bets". The Economist. November 10, 2021. Retrieved June 7, 2022.
  23. ^ Ignatius, David (November 1, 2013). "More chatter than needed". Washington Post. Retrieved May 6, 2014.
  24. ^ Bender, Jeremy (April 3, 2014). "Huge Experiment Finds Regular Folks Predict World Events Better Than CIA Agents". Business Insider. Retrieved May 6, 2014.
  25. ^ "The Surprising Accuracy Of Crowdsourced Predictions About The Future. Do you know whether Turkey will get a new constitution? It turns out you do: A group of well-informed citizens can predict future events more often than any foreign policy expert or CIA analyst". Co.exist. April 21, 2014. Retrieved May 6, 2014.
  26. ^ Harford, Tim (2014-09-05). "How to see into the future". Financial Times. ISSN 0307-1766. Retrieved 2014-09-05.
  27. ^ Hamilton, Keegan (8 January 2015). "How US Agencies Are Using the Web to Pick Our Brains". Washingtonian. Retrieved 2015-01-24.
  28. ^ Burton, Tara (2015-01-20). "Could you be a 'super-forecaster'?". BBC Future. Retrieved 2015-01-21.
  29. ^ Jensen, Nathan (2015-01-21). "Experts see a Republican Senate and fast-track authority for Obama as keys to new trade agreements". The Washington Post. ISSN 0190-8286. Retrieved 2015-01-21.
  30. ^ Mellers, Barbara; Michael C. Horowitz (2015-01-29). "Does anyone make accurate geopolitical predictions?". The Washington Post. ISSN 0190-8286. Retrieved 2015-01-30.
  31. ^ "Feature story: Bob Sawyer of Woodside discovers his latent talent in forecasting". Retrieved 2015-03-17.
  32. ^ Dribben, Melissa; Inquirer Staff Writer (2015-02-04). "Fortune telling: Crowds surpass pundits". Retrieved 2015-02-06.
  33. ^ Sunstein, Cass R.; Hastie, Reid (2014-12-23). Wiser: Getting Beyond Groupthink to Make Groups Smarter. Harvard Business Review Press. ISBN 978-1-4221-2299-0.
  34. ^ "Who's Best at Predicting the Future? (and How to Get Better)". Psychology Today. Retrieved 2015-07-11.
  35. ^ Mellers, Barbara; Stone, Eric; Murray, Terry; Minster, Angela; Rohrbaugh, Nick; Bishop, Michael; Chen, Eva; Baker, Joshua; Hou, Yuan; Horowitz, Michael; Ungar, Lyle; Tetlock, Philip (2015-05-01). "Identifying and Cultivating Superforecasters as a Method of Improving Probabilistic Predictions". Perspectives on Psychological Science. 10 (3): 267–281. doi:10.1177/1745691615577794. ISSN 1745-6916. PMID 25987508. S2CID 3118872.
  36. ^ Tetlock, Philip E.; Gardner, Dan (2015-09-29). Superforecasting - The Art and Science of Prediction. New York: Crown. ISBN 978-0-8041-3669-3.
  37. ^ Gardner, Dan (2010-10-12). Future Babble: Why Expert Predictions Fail - and Why We Believe Them Anyway. McClelland & Stewart.
  38. ^ "Unclouded vision". The Economist. 2015-09-26. ISSN 0013-0613. Retrieved 2015-09-24.
  39. ^ Zweig, Jason. "Can You See the Future? Probably Better Than Professional Forecasters". The Wall Street Journal. Retrieved September 25, 2015. I think Philip Tetlock's "Superforecasting: The Art and Science of Prediction," ..., is the most important book on decision making since Daniel Kahneman's "Thinking, Fast and Slow."
  40. ^ Frick, Walter. "Question Certainty". Harvard Business Review. Retrieved 2015-09-26.
  41. ^ McEnroe, Colin; Wolf, Chion. "The Colin McEnroe Show". WNPR. National Public Radio. Retrieved October 1, 2015.

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