Is the range of ACT and SAT scores, that Stanford displays to give applicants an idea of where to score, super scored scores or not?
For ACT, it is based on composite scores not superscores. On SAT, Stanford actually reports its middle 50% range for both the math and reading/writing sections and not the composite. To do so it uses the highest math or separately the highest reading/writing scores of those who enroll and thus superscores in that sense but that does not mean any superscored tests of an individual necessarily fall within that percentage, e.g., for 2017 it reported that the 25% range for math was 700 and reading/writing 690, totaling 1390, but someone who via superscore had a 750 math score and only a 640 reading/writing score, and thus a 1390 total, was actually not at that 25% range – they would have been higher for math and lower for reading/writing. Moreover, the score ranges for both tests are reported for those who actually enroll and not those who are admitted, and the admitted range could be different, e.g., if a large number of extremely high scorers are admitted and choose to attend another college, the enrolled ranges you are seeing online could actually be lower than the admitted ranges.