F-Test

The F-Test is a test for equal variances comparing the variations of two groups when the distributions are normal (X in two groups only).
Bartlett Test

Bartlett Test

The Bartlett-Test is a test for equal variances comparing the variations of more than two groups when the distributions are normal (X in more than two groups). Read also: F-Test, Levene-Test, Multiple...

Box-Cox Power Transformation

The statisticians Box and Cox developed this function which applies a mathematical operation to a set of non-normal data, transforming it into one that more closely approximates a normal distribution. It identifies an appropriate exponent (Lambda) to transform data...

Cpk

The Cpk-Index (Critical Process Capability; k: “Katayori”, Japanese for bias) compares the distance from the process center to the nearest Specification Limit (how the process should be) to the process spread (how it is). The short-term standard deviation...

Cp

The Cp-Index (Process Capability) compares the tolerances of the process (how it should be) to the process spread (how it is). The short-term standard deviation sST is calculated using short term data, usually 25-50 samples within a short time frame – i.e. days....