Quantoid Lesson - Composite standard scores will not necessarily equal the ave of the test SSs

I continue to field emails (not a large number...but a sufficient quantity to result in this post) for an explanation why the WJ III cluster standard scores often do not approximate the arithmetic average of the test standard scores that comprise a particular cluster.

I remembered writing about this in 1994 with regard to the WJ-R Broad Cognitive Ability cluster score. So, I scanned those pages into a pdf and they are now available by clicking here.