Home/Discussion Groups/Session 1: Credences and Confidence

Session 1: Credences and Confidence

This session introduces credences as degrees of confidence rather than simple yes-or-no belief.

Concept Focus

A credence is a confidence level. Instead of saying only “I believe it” or “I do not believe it,” participants practice saying “I am 60 percent confident” or “I lean toward this, but weakly.”

The session helps participants see why binary belief is too crude for real reasoning. Many claims deserve partial confidence, and many arguments fail because people treat partial confidence as certainty.

Historical Example

Before weather forecasting became data-rich, people often relied on sayings, local memory, and visible signs. Modern forecasting improved by turning uncertainty into probabilities: a 30 percent chance of rain is not a failed prediction if rain does not occur.

This example shows why confidence levels matter. The point is not to erase uncertainty, but to make uncertainty useful.

Contemporary Issue

Online headlines often push readers toward instant certainty. A group can ask: what confidence would this headline deserve before reading the full article? What confidence after checking the source, evidence, and context?

Adjacent References

These are starting points rather than exhaustive citations. They connect this page to nearby work in probability, calibration, cognitive bias, and social epistemology.

|Daniel Kahneman and Amos Tversky, "Judgment under Uncertainty: Heuristics and Biases" (1974).
|Sarah Lichtenstein, Baruch Fischhoff, and Lawrence D. Phillips, "Calibration of Probabilities" (1982).

Discussion Questions

Questions with expandable guidance

Open each question for facilitator notes, examples, scenarios, and feedback. The aim is careful discussion at a senior high school reading level.

Question 1Choose a common claim and assign it a confidence level. What makes that number too high, too low, or reasonable?+

GuidanceEncourage ranges: 40-60 percent is often more honest than 52 percent. Ask what evidence would move the number by at least 10 points.

Hypothetical ScenarioA friend says, “I am sure this new study proves coffee is bad for everyone.” What confidence would you assign before reading the study?

Contemporary IssueHealth headlines, sports predictions, college admissions guesses, and economic forecasts all invite confidence levels rather than simple belief.

FeedbackGood responses explain the number. Weak responses give a number with no evidence or update condition.

Question 2When does saying “I believe it” hide too much information?+

GuidanceHave participants compare “I believe it at 51 percent” with “I believe it at 95 percent.” Both may count as belief, but they should not guide action in the same way.

Historical ExampleWeather forecasting became more useful when it moved from yes/no predictions to probabilities such as a 30 percent chance of rain.

FeedbackThe key insight is that belief has strength. Two people may both “believe” something while holding very different levels of confidence.

Question 3Why do people often prefer certainty language even when they are uncertain?+

GuidanceLook for social rewards: confidence can sound smart, loyal, brave, or decisive. Uncertainty can be mistaken for weakness.

Hypothetical ScenarioIn a group project, one student is 60 percent confident the plan will work. Another says, “It will definitely work.” Who sounds stronger, and who may be reasoning better?

FeedbackGood answers separate emotional comfort from epistemic accuracy.