The one sentence summary
It is possible to increase the accuracy of forecasts by acting as superforecasters do.
WHAT THE BOOK SAYS
- Philip Tetlock ran a twenty year study showing that so-called experts were only slightly better at prediction than random guesswork, or, as he put it, “a dart throwing chimp”.
- There is however a group of ordinary people that can predict the future with a degree of accuracy 60% greater than average. They are superforecasters. 3,000 of them were recruited in 2008 by a US government backed initiative called IARPA. This is how they do it:
- Concentrate on clear questions that can be answered, albeit with hard work.
- Break seemingly intractable problems into tractable sub-problems.
- Strike the right balance between inside and outside views.
- Strike the right balance between under- and overreacting to evidence.
- Look for the clashing causal forces at work in each problem.
- Strive to distinguish as many degrees of doubt as the problem permits, but no more.
- Strike the right balance between under- and overconfidence.
- Look for the errors behind your mistakes but beware of rear-view mirror hindsight biases.
- Bring out the best in others and let others bring out the best in you.
- Master the error-balancing cycle: try, fail, analyse, adjust, try again.
- Don’t treat commandments as commandments.
WHAT’S GOOD ABOUT IT
- The dragonfly eye is made up of thousands of tiny lenses, each with a slightly different perspective, allowing it to see in almost every direction simultaneously. An aggregation of views is what makes accurate forecasts.
- Good forecasters have no illusion of control or prediction. It is important to appreciate the limits of prediction, without necessarily being pessimistic about their value.
- The US National Intelligence Agency has a scale for certainty v. the general area of possibility.
100%: certain
93% (give or take about 6%): almost certain
75% (give or take about 12%): probable
50% (give or take about 10%): chances about even
30% (give or take about 10%): probably not
7% (give or take about 5%): almost certainly not
0%: impossible
- Old joke: statisticians sleep with their feet in an oven and their head in the freezer because the average temperature is comfortable.
WHAT YOU HAVE TO WATCH
- Not much. It’s longer than it needs to be, but the points are excellent.