false positive

A decision procedure tries to say whether some hypothesis H holds or does not (usually based on some observed data, O). If it says H does hold, it is said to give a positive. If, in fact, H does not hold, this is a false positive.

For procedures that always decide in the positive or in the negative, there is usually a tradeoff between false negatives and false positives.

See also sensitivity.

A 'false positive' can occur on a home pregnancy test. This result means that the at-home testing results report that the woman is pregenant when she is, in fact, not. At-home pregnancy tests are sometimes sold in 2-packs for women to use both tests at the same time. Testing differently using the same method at the same time is an indication of a false positive or false negative result.

A false positive may occur if the woman has levels of hCG in her blood from a recent pregnancy or miscarriage. It can also occur if you are receiving fertility injections to induce ovulation.

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In biometrics, this term refers to the case where an authentication system erroneously grants access to an authorized entity.