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 ?
Mathematically, it is equal to the ratio of true negatives over true negatives plus false negatives (see figure 1).
0% (36 of 50) were true negatives (Figure 2, G) and 28% (14 of 50) were considered false negatives.
Test Efficiency(*) Conventional Tests Criteria ICL TV True positive 9 7 9 True negative 16 17 20 False positive 4 3 0 False negative 1 3 1 Sensitivity, % 90 70 90 Specificity, % 65 85 100 Positive predictive value, % 56 70 100 Negative predictive value, % 93 85 95 Efficiency, % 73 80 97 Tests ICL + TV ICL or TV True positive 6 10 True negative 20 17 False positive 0 3 False negative 4 0 Sensitivity, % 60 100 Specificity, % 100 85 Positive predictive value, % 100 77 Negative predictive value, % 83 100 Efficiency, % 87 90 (*) ICL indicates intracytoplasmic lumen; TV, transgressing vessels.
Myeloid Immature Atypical Analyzer Blasts Precursors Gran Lymph XE-2100 True positive, n 18 104 77 8 True negative, n 438 303 327 441 False positive, n 25 53 75 23 False negative, n 5 26 7 14 Sensitivity, % 78 80 92 36 Specificity, % 95 85 81 95 Efficiency, % 94 84 83 92 NE-8000 True positive, n 15 61 27 9 True negative, n 411 241 356 433 False positive, n 52 115 46 31 False negative, n 8 69 57 13 Sensitivity, % 65 47 32 41 Specificity, % 89 68 89 93 Efficiency, % 88 62 79 91
Studies suggest that the Octava Pink test confirms true negative mammography results with high accuracy, while identifying the presence of cancer in more than half of the cases when the mammography result is a false negative and cancer is actually present.
Phe], HP, and PKU), performance measures were based on two numbers: the true positives (HP, PKU) and the true negatives (CTRL, [FP.
1 True Positives 9 7 12 True Negatives 5 8 10 False Positives 2 0 (0.
In an ideal world, only true positives and true negatives occur.
Four measures typically help in evaluating classifiers: The number of cases the classifier got correct--True Positives and True negatives and the number of cases the classifier got incorrect -False positives and false negatives.
The true positives (TP) and true negatives (TN) are correct classifications.
Calculation: True Negatives / (True Negatives + False Positives) [Brunette, 1996].
Because almost all of the data which would provide evidence for the validity of a negative clinical test (both true negatives and false negatives) was not collected, this research is unable to provide a valid estimate of specificity.