Probabilistic Expression of Confidence
Redefining confidence as a numerical probability (e.g., 73%) allows for mutual recognition of uncertainty and invites open debate, rather than asserting certainty.
THE IDEA
Redefining confidence
When you express uncertainty to someone who knows about communicating that way, the mutual recognition is like a light switch turning on. When I was early in the process of writing this book, I had lunch with Stuart Firestein. We had barely exchanged pleasantries when the waiter came to take our order. The waiter was not a native English speaker, and I have a lot of dietary restrictions that are difficult enough to communicate to someone who shares my first language. When the waiter walked away, I said, 'Well, that’s seventy-three percent.' Stuart started laughing, because he immediately knew what I meant. 'I think it’s lower than that,' he said. 'Maybe somewhere in the forties that he’s going to get your order right.' My declaration of uncertainty invited the discussion about whether my lunch order would be correct. That seems like a small thing, but when you express uncertainty in this way, you will invite debate about more significant topics.
When to use it
When estimating project deadlines, provide a probability of completion by that date.
During team meetings, have each member state their confidence in their recommendation on a scale of 0-100%.
When evaluating a strategic move, assign a probability of success and discuss the assumptions behind it.
When receiving advice, ask 'How confident are you in that advice?' to encourage calibrated thinking.
FROM THEORY TO EVERYDAY LIFE
In practice
Lunch Order Uncertainty
During a lunch meeting with Stuart Firestein, the author expressed uncertainty about the waiter getting the order right by saying 'seventy-three percent'. Firestein responded with an even lower probability, sparking a debate about the likelihood. Expressing confidence as a probability invites calibration and discussion.
A MOMENT TO REFLECT
Put it to work.
Think of a recent situation where you were absolutely sure about something. What would have happened if you had expressed it as a probability instead?
How can you incorporate probabilistic thinking into your daily conversations to foster better decision-making?
When someone states an opinion with high confidence, how would you ask them to convert that into a percentage?
References
- Going Bald Isn’t Your Mother’s Fault; Maternal Genetics Are Not to Blame — Susan Scutti (2015)
- Coffee Isn’t Made from Beans, You Can’t See the Great Wall of China from Space and Everest ISN’T the World’s Tallest Mountain: The Top 50 Misconceptions That Have Become Modern Day ‘Facts’ — Emma Glanfield (2015)
- List of Common Misconceptions — Wikipedia (2017)
- They Saw a Game — Hastorf and Cantril
CONTINUE THE CONVERSATION
Source texts
- Thinking in Bets Making Smarter Decisions When You Dont Have All the Facts (Annie Duke)