AI Glossary Term

What does “False Negative” mean?

Definition

An incorrect prediction where a model misses a true positive case.

How False Negative works

Diagram for False Negative, a two-by-two grid of Reality against Model said: True positive; False negative: missed it; False positive; True negative.Model saidPositiveNegativeActuallypositiveTrue positiveFalsenegative:missed itActuallynegativeFalse positiveTrue negativeReality

Example

A cancer-screening model looks at a scan that does contain a tumor but says 'no finding'. That is a false negative. In screening, these misses are often considered more costly than false alarms.

Why it matters

Which error is worse depends on the task. Understanding false negatives helps decide thresholds and when human review is needed.

Common questions

How is a false negative different from a false positive?

A false negative misses something that is there. A false positive flags something that is not.

Which metric reflects false negatives?

Recall: it drops as false negatives rise.

Can I reduce false negatives?

Usually by lowering the decision threshold, which tends to raise false positives. Trade-offs are unavoidable.

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