I had my daughters initial testing done at a Ph.D. Level school psychology program at a university. This university employs several very well known creators of these tests and when I asked about the extended norms the evaluators checked with them and this is what I was told. "Extended norms are only to be used when an examinee receives full credit on every item in a subtest and receives a perfect raw score, otherwise extended norms are not statistically necessary, they are for the students who max out an area of the test, not students who do very very well for their age." The person who answered helped create the norms, so I imagine this answer was accurate. In short they said most of the time extended norms really should not be calculated.
Are you sure that's what they said? Mathematically this is quite bizarre.
