Contents
- Index
Test of Fit
To test whether a distribution fits a set of data, Distribution Analyzer uses the transformation to normality associated with that distribution and transforms the data. It then applies a normality test to see if the transformed values fit the normal distribution. Distribution analyzer includes three normality tests:
Anderson-Darling Test (AD)
Shapiro-Wilks Test (SW)
Skewness-Kurtosis All Test (SK All)
The above three tests are designed to detect all departures form normality. They answer the question: "Does the data fit the normal distribution?"
A fourth specialized test is:
Skewness-Kurtosis Specific Test (SK Spec)
This test is designed to only reject for specific departures that invalidate the confidence statements associated with variables sampling plans and normal tolerance intervals. It is designed to answer the question: "Is it OK to use a variables sampling plan or normal tolerance interval?" Passing this test is sufficient justification to use a variables sampling plan or normal tolerance interval, even if the other three tests fail.