I really don�t know much about the ITBS. The only evidence that I see that the SS could possibly be on a continuum is to compare DS�s math totals from last year and this year. Each were/are 99th percentile. The SS are 299 (6th) and 311 (7th).

Either way, I don�t put too much stock into grade level group testing. The above level achievement tests are far more meaningful with this population.