Base rate neglect

Presents a number without the baseline needed to understand what it means.

Specimen

Forty people in this town developed the condition last year. That's a health crisis.

Fabricated passage — teaching example designed for clarity.

Data & evidence issue / base rate neglect

base rate neglect — 40 cases presented without population size or historical baseline

Dissection

Forty people in this town developed the condition last year. That's a health crisis.

  • no population denominator
  • no historical comparison
  • 40 could be high or low

Field notes

Family
Data & evidence issue
Habitat
health reporting, crime statistics, environmental journalism
Frequency
found in 11% of analyzed articles
Confused with
Misleading statistic , Cherry-picking

In the wild

"Three hundred people were arrested at the protest — an alarming number by any measure."

News coverage, regional daily, January 2026

"Fifteen schools in the county reported the issue this term — up from last year."

Education reporting, regional broadsheet, March 2026

Why it works

Absolute numbers feel significant in isolation. Without the denominator or historical comparison, there's no frame to judge whether the number is high or unremarkable.

Counter-move

Ask: out of how many? What was it last year? What's the expected rate?

See it flagged in real articles while you read.

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