Norming data matters. By creating sub-sets/groups, the data can be more precise, thereby supporting certain stakeholders with the dialogues they are having around data. Because the ISEE and SSAT are not using the same test design or norming data, the results are lower than on MAP while these are still standardized tests. This creates confusion and some might perceive MAP norming to be less competitive if they have students moving on to private high schools or to universities because the norms for the ISEE (connected to ERB) and to the SSAT are more demanding (the percentiles don't align between MAP and the other tests). There are close to 90 French American schools in the US alone and I'm pretty sure all of the schools doing MAP at them would be eager to benefit from such a norming group.