Base Rate Fallacy
A vivid case-specific clue can receive too much weight, or the relevant starting frequency too little, when people estimate how likely an outcome is.
Quick answer
What does Base Rate Fallacy mean?
Base-rate neglect means giving too little weight to a relevant starting frequency when combining it with new case-specific evidence. A useful explanation shows why the reference class fits, puts true and false positives on the same denominator and keeps uncertainty visible.
Public evidence overview
One checked source, with its limits.
This preview is not the complete evidence base. Use it as a question to investigate in your own product, not as a prediction of what an individual will do.
Pictorial Representations in Statistical Reasoning
Research-assisted source review
- What it supports
- Icon-based representations produced a consistent reasoning advantage over the other pictorial formats tested, offering support for countable frequency displays.
- Where it may not transfer
- The studies used structured Bayesian word problems and measured solution performance rather than consequential choices. An icon array can add visual and accessibility burden, and its benefit depends on labels, grouping, denominator and task.
See how sources and limitations are checked in our editorial method.
Member depth
Continue into the complete evidence and application.
Practitioner includes the complete checked source set, study context and practical takeaways for this ingredient. The public overview above remains available without upgrading.