The Increment Weighting Error

The low-key position of the Increment Weighting Error IWE in this fourth edition of the book is justified by the fact that for the moments of this error to be accessible in a logical way it is of the utmost importance to make sure the sample selection process is absolutely correct. With this important restriction in mind, the Increment Weighting Error is defined as the error whose moments are the difference between the moments of the Heterogeneity Fluctuation Error HFE and the moments of the Quality Fluctuation Error QFE .