It just means that while the norm sample may have dropped 1 to 5 points (ex 130 to a 127, 157-154, etc) when they calculate the standard score from the raw score, one of my sons score dropped from the 180's to the 150's with the new scoring norms.

In very basic English, as I understand, it seems that every few years the population changes and tests must be re-normed to provide better accuracy. It can however affect the scores of certain populations.

Hopefully someone else may have a better explanation.

Crisc