Looking for longitudinal percentile growth standards in nationally normed tests.

The situation is this… I have a set of students in a relatively small dataset who are all from the same family. They’ve shown tremendous progress in nationally normed test results over the years. I want to know just how rare this performance is (it could be common, but I doubt it).

For example… Student A - 1st Grade Reading, 1st Percentile - 1st Grade Math, 1st Percentile - 6th Grade Reading, 71st Percentile - 6th Grade Math, 57th Percentile

Student B - 1st Grade Reading, 1st Percentile - 1st Grade Math, 1st Percentile - 5th Grade Reading, 37th Percentile - 5th Grade Math, 55th Percentile

Student C - 1st Grade Reading, 7th Percentile - 1st Grade Math, 4th Percentile - 5th Grade Reading, 33rd Percentile - 5th Grade Math, 26th Percentile

(Students B and C are twins, Student A is their older sibling)

My dataset is relatively small-n (SPED-only) but almost everybody else in it is pretty flat—if you were sub-10th percentile in 1st, you’re sub-10 in 5th. I’m considering doing a case study with this family, but I want to be sure I’m chasing an effect that is rare enough to matter. Since my dataset is small-n I’m loathe to just use it as my internal metric.

Does anybody have a notion of how rare growth is like this? I mean, do we see this type of growth in 5% of American students? 25%? Is Student A coming close to breaking records (that student is a clear outlier in my dataset, but again, small-n). When I search for things like “longitudinal improvement by-student” I’m not getting much other than just the boilerplate stuff from MAP and NAEP.

Any help is appreciated!

Submitted March 15, 2024 at 08:21AM by Kris_Include https://ift.tt/wjSzTZi