How Sure Are You?
Galef uses Spock’s confident predictions to discuss calibration. Calling something impossible is a stronger claim than assigning it a small chance; one success can contradict impossibility without disproving a low nonzero probability.
THE IDEA
How Sure Are You?
In a scene in the 2016 movie Star Trek Beyond, a spaceship careens across the sky.1 It’s being piloted by Captain Kirk, who is hot on the tail of three enemy ships headed straight for the center of a city, where they intend to detonate a superweapon. Kirk’s right-hand man, Commander Spock, yells to him: “Captain, intercepting all three ships is an impossibility!”
An impossibility. The words sound so authoritative, so definitive. And yet less than sixty seconds later, Kirk has figured out how to maneuver in front of the enemy ships, stopping them with his own ship’s hull before they can reach their destination.
If you’ve watched much Star Trek before, this won’t surprise you. Spock doesn’t have a great track record when it comes to making accurate predictions. “There’s only a very slight chance this will work,” Spock warns Kirk in one episode of the original TV show, right before their plan works.2 The odds of survival are “less than seven thousand to one,” Spock tells Kirk in another episode, shortly before they escape unharmed.3 The chance of finding survivors is “absolutely none,” Spock declares in yet another episode, right before they discover a large colony of survivors.4
The examples make different kinds of claims. An event’s occurrence contradicts a literal claim of impossibility. It does not, by itself, refute a prediction that the event has a small nonzero chance; assessing that prediction requires more evidence.
When to use it
When estimating project timelines, avoid overconfidence by considering past failures.
In risk assessment, explicitly list reasons why a plan might fail.
During strategic planning, seek dissenting opinions to test your certainty.
FROM THEORY TO EVERYDAY LIFE
In practice
Spock's Impossibility Prediction
In Star Trek Beyond, Spock declares that intercepting all three enemy ships is an impossibility, but Captain Kirk accomplishes it within seconds.
Slight Chance Success
In an episode of the original Star Trek, Spock says 'There's only a very slight chance this will work' right before the plan works. Success alone does not establish that the stated small chance was inaccurate.
A MOMENT TO REFLECT
Put it to work.
When have you made a confident prediction that turned out wrong?
How can you calibrate your certainty levels to be more accurate?
What techniques can you use to challenge your own assumptions before making a decision?
CONTINUE THE CONVERSATION
Source texts
- The Scout Mindset (Julia Galef)