T-Score is just their alternate way of showing standard deviations (avg 50, 10 per SD; vs. IQ that is ~avg100 with 15 per SD.) Since they only report out to 4 standard deviations, then I think you'd call that hititng the ceiling with a 90. That just may be the max reliability they have.
For the age equivalencies... some abilities change less as kids get older or have a mean that plateaus after a certain age (e.g. average of 24 for 8 yr, 26 for 9 yr, 28 for 10 yr, 28 for 11 yr, 28 for 12 yr; would be a plateau at a score of 28 and would report as equiv age 10+) Matrices could be something that some kids mature into quicker giving a less bell-like curve at younger ages.
Hope that helps some; I'm not specifically familiar with that test, but with testing/stats in general.
Last edited by Zen Scanner; 07/17/12 02:16 PM.
