Lesson · 4 min Steady
How Sure Are You?
In one line Put a number on your confidence, then check later whether your sure answers were right as often as you said.
Most of us feel more or less sure without saying how sure. A number makes it checkable. If you say you are 90 percent sure about ten things, about nine should turn out true. That match between confidence and results is called calibration.
Many people are overconfident. In quiz studies, answers people marked 90 percent sure were right only about 75 percent of the time. A few are the opposite and doubt things they know well. Either way, the feeling of certainty is a poor judge of itself.
The fix is practice. Write a prediction, give a percentage, and record what happened. After a few weeks you can see the gap between how sure you felt and how often you were right, and adjust.
The ninety-percent guesses
Kai writes ten predictions about the week, such as whether a bus will be on time, and gives each a percentage. Seven he marks at 90 percent.
On Sunday he finds five of those seven came true. His 90 percent answers were right about 70 percent of the time. Next week he marks himself at 70 percent for the same kind of prediction.
Try this today Make three predictions this week with a percentage each, then score yourself on Sunday.
Cite or share this lesson
A plain reference you can paste into notes or an essay:
Quest2Reason. “How Sure Are You?.” https://quest2reason.com/learn/lesson/how-sure-are-you. Accessed 13 November 2026.
Sources
- Stanford Encyclopedia of Philosophy, “Formal Representations of Belief” — Covers degrees of belief and how they can be measured against outcomes.
- Wikipedia, “Calibrated probability assessment” — Matching stated confidence to results.
- Philip Tetlock and Dan Gardner, Superforecasting (2015) — Calibration in practice: forecasters who put numbers on their confidence and score themselves. Paraphrased; nothing is quoted.
- Asher Koriat, Sarah Lichtenstein and Baruch Fischhoff, “Reasons for Confidence” (1980) — A study of overconfidence: answers given 90 percent confidence were right well under 90 percent of the time.