true negative


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Related to true negative: False Negative Rate

true negative

Statistics A negative test result, that accurately reflects the tested-for activity of an analyte

specificity 

The extent to which a test gives results that are free from false positives (i.e. people found to have the defect when they are actually free of it). The fewer the number of false positives, the greater is the specificity of the test. It is usually presented as the percentage of people truly identified as not defectives, or normal, referred to as true negatives, D (or correct reject), divided by the total number of not defectives or normal people tested. The total number includes all the true negatives, D, plus the false positives, B (or false alarm). Hence
See sensitivity.
References in periodicals archive ?
Forty-two stations show percent true negative values of 100%, indicating that all estimated 90th percentile values of fecal coliform concentrations of these stations appear in the true negative zone, representing no fecal-contaminated shellfish.
But on this reading, it is unclear what, exactly, true negative causal statements express.
There were 73 true positive (TP) specimens and 25 true negative (TN) observations for a total of observations in the true quadrants.
Specificity is the proportion of true negatives or those who would not die that were judged negative by the test.
(12) Alternatively and equivalently, one can ask how many false positives one can accept for every true positive, or how many false negatives one can accept for every true negative. Sometimes this is an easier method to implement, but it is a detail that will not be discussed here.
Increases the number of true positive and true negative test results
[2] Nonstandard abbreviations: SAMHSA, Substance Abuse and Mental Health Services Administration; OF, oral fluid; DUID, driving under the influence of drugs; THC, [[DELTA].sup.9]-tetrahydrocannabinol; 11-OH-THC, 11-hydroxy-THC; THCCOOH, 11-nor-9-carboxy-THC; LOQ, limit of quantification; IV, intravenous; GC-MS-MS, gas chromatography-tandem mass spectrometry; 2D, 2-dimensional; CBD, cannabidiol; CBN, cannabinol; LOD, limit of detection; [[DELTA].sup.8]-THC, [[DELTA].sup.8]-tetrahydrocannabinol; TP, true positive; FN, false negative; TN, true negative; FP, unconfirmed positive.
High Confidence Medium/Low Confidence Total Call In-Grammar Out-Of-Grammar Positive True Positive a False Positive c a + c Negative False Negative b True Negative d b + d Total a + b c + d To draw an ROC curve, only the true positive rate (TPR) and false positive rate (FPR) are needed.
[18F]fluorocholine combined in-line positron emission tomography-computerized tomography was true positive in 1, false-positive in 2, false-negative in 9 and true negative in 8 patients.
The percentages of voters saying they are less likely to vote for a candidate because of one of their personal associations probably overstates the true negative impact for the candidates, mainly because voters who might not seriously consider voting for a candidate in the first place (e.g., Democrats for McCain or Republicans for Obama) often respond that they are "less likely" to vote for that candidate.