type II error


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error

 [er´or]
a defect or mistake in structure or function.
inborn error of metabolism a genetically determined biochemical disorder in which a specific enzyme defect produces a metabolic block that may have pathologic consequences at birth, as in phenylketonuria, or in later life.
measurement error the difference between what exists in reality and what is measured by a measurement method.
Type I error the rejection of a null hypothesis that is true.
Type II error acceptance of a null hypothesis that is false.

er·ror of the sec·ond kind

in a Neyman-Pearson test of a statistical hypothesis, the probability of accepting the null hypothesis when it is false; the complement of the power of the test.

type II error

β error, false-negative error Statistics Acceptance of the null hypothesis when it is false or incorrect, or the error of falsely stating that two proportions are not significantly different when they actually are. See Null hypothesis Cf Type 1 error.
References in periodicals archive ?
FIGURE 1 TYPE I AND TYPE II ERRORS Proper Course of Action Take No Action Take Action Take No I II Action Correct Type I Decision Error Decision Take III IV Action Type II Correct Error Decision FIGURE 2 THE BASIC DECISION MATRIX OF POLICYMAKERS Choice 1 Choice 2 Incremental Dramatic Action Action--Mild No Mitigation Action Proper Course of Action I II Correct Decision Type I Error III IV Type II Error Correct Decision TABLE 1 FOUNDATIONS OF CONSTRUCTIVIST VS.
Cohen (1988) suggested that the Type II error risk should be 4 times as great as the Type I error risk to ensure adequate analyses without having to use unrealistically high sample sizes for social science research.
Although previous statistical methods give data on quantity of type I error to researchers, the occurrence of type II error mostly remains unknown (Stefano, 2001).
Courts, agencies, and academics have reacted to antitrust's unusual vulnerability to error by adopting a bias in favor of false negatives (Type II errors).
For most groups, Type II error is large relative to Type I error.
Empirical studies (e.g., Ferron, Foster-Johnson, & Kromrey, 2003; Ferron & Ware, 1995) concur with the latter statement showing that Type II errors ate the main problem, while Type I errors ate usually controlled.
A Type II error in this experiment occurs when R = 1 and P < 1.
When FDA commits a Type I error, "the status quo will be disrupted and people will die much sooner than they otherwise would." When the agency commits a Type II error, people will be denied a treatment for their illness, but "the status quo will remain" (p.
Classification Error Rates and Accuracy Levels of 354 mixed industry firms and 40 retail industry firms Year 1 Year 2 Year 3 Mixed Industries Type I error 15% (15%) 30% (30%) 36% (37%) Type II error 10% (11%) 12% (14%) 16% (18%) Overall error 12% (13%) 21% (22%) 26% (27%) Overall accuracy of classification 88% (87%) 79% (78%) 74% (73%) Retail Industry Type I error 30% (30%) 65% (65%) 50% (50%) Type II error 10% (10%) 5% (5%) 10% (10%) Overall error 20% (20%) 35% (35%) 30% (30%) Overall accuracy of classification 80% (80%) 65% (65%) 70% (70%) Note: 1) B--bankrupt firms; NB--nonbankrupt firms 2) Type I error = misclassification of bankrupt firms 3) Type II error = misclassification of nonbankrupt firms 4) Cutoff value = 0.5 5) Year 1 means 1 year before bankruptcy, and so on.
[TrT.sub.A] = Type II error Correct decision Type II error [TrT.sub.B] 3.
The second class of errors, termed Type II errors or false negatives, occur when the system fails to detect or identify that which the system has been designed to look for.
Given the possibility of a type II error and the absence of any downside to involvement with Alcoholics Anonymous, an argument can be made for continuing to refer patients to this group.