A method for adjusting a complex index with inherent anomalies due to the presence of multiple quality levels of the same indexed characteristic in a single sample. Select embodiments of the present invention provide for adjusting the complex index where at least two or three quality levels of the same characteristic are present in the inspection sample. Various embodiments of the present invention provide an adjustment for a pavement condition index (PCI) established with ranges of severity estimated as low, medium and high for each distress type.