GrubbsTest Class

public sealed class GrubbsTest : OneSampleTest

Public NotInheritable Class GrubbsTest
	Inherits OneSampleTest

public ref class GrubbsTest sealed : public OneSampleTest

[<SealedAttribute>]
type GrubbsTest =  
    class
        inherit OneSampleTest
    end

The GrubbsTest type exposes the following members.

	Name	Description
	GrubbsTest	Constructs a new Grubbs test for a single outlier.
	GrubbsTest(VectorDouble)	Constructs a new Grubbs test for a single outlier.
	GrubbsTest(VectorDouble, HypothesisType)	Constructs a new Grubbs test for a single outlier.

	Name	Description
	Distribution	Gets the probability distribution used in the hypothesis test. (Inherited from HypothesisTest.)
	HypothesisType	Gets or sets whether the test is one or two-tailed. (Inherited from HypothesisTest.)
	Name	Gets the name of the hypothesis test. (Overrides HypothesisTestName.)
	PValue	Gets the probability that the test statistic would take on the calculated value under the alternate hypothesis. (Inherited from HypothesisTest.)
	Sample	Gets or sets the variable the test is to be applied to. (Inherited from OneSampleTestT.)
	SignificanceLevel	Gets the significance level used to test the null hypothesis. (Inherited from HypothesisTest.)
	Statistic	Gets the value of the test statistic. (Inherited from HypothesisTest.)

	Name	Description
	Equals	Determines whether the specified object is equal to the current object. (Inherited from Object.)
	GetConfidenceInterval	Returns the confidence interval for the test parameter for the default confidence level. (Inherited from HypothesisTest.)
	GetConfidenceInterval(Double)	Returns the confidence interval for the test parameter for the specified confidence level. (Inherited from HypothesisTest.)
	GetHashCode	Serves as the default hash function. (Inherited from Object.)
	GetLowerCriticalValue	Gets the lower critical value for the hypothesis test's current significance level. (Inherited from HypothesisTest.)
	GetLowerCriticalValue(Double)	Gets the lower critical value for the hypothesis test at the specified significance level. (Inherited from HypothesisTest.)
	GetPValue	Gets the probability that the test statistic would take on the calculated value under the specified alternate hypothesis. (Inherited from HypothesisTest.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	GetUpperCriticalValue	Gets the upper critical value for the test statistic at the hypothesis test's current significance level. (Inherited from HypothesisTest.)
	GetUpperCriticalValue(Double)	Gets the upper critical value for the test statistic at the specified significance level. (Inherited from HypothesisTest.)
	Reject	Returns whether the null hypothesis is rejected using the default significance level. (Inherited from HypothesisTest.)
	Reject(Double)	Returns whether the null hypothesis is rejected using the specified significance level. (Inherited from HypothesisTest.)
	Summarize	Returns a string containing a human-readable summary of the object. (Inherited from HypothesisTest.)
	Summarize(SummaryOptions)	Returns a string containing a human-readable summary of the object using the specified options. (Inherited from OneSampleTestT.)
	ToString	Returns a string that represents the current object. (Inherited from HypothesisTest.)

Use the GrubbsTest class to test whether the value with greatest deviation from the mean in a sample is an outlier.

The test has two-sided and one-sided versions. In the one-sided version, the null hypothesis is that the smallest (one-tailed lower) or largest (one-tailed upper) value in the sample is not an outlier. In the two-sided version, the null hypothesis is that neither the smallest or the largest value are outliers.

This test assumes that the sample is drawn from a normal distribution. It can only test for a single outlier. If you suspect there is more than one outlier, the GeneralizedEsdTest is the test of choice.

Reference