Unfortunately gaming the system is still a temptation.
By rewarding growth, schools are incentivized to prevent earlier grades from doing too well.
One student with potential pushing the overall performance higher than that school might like for that year might be purposefully stunted in order to allow room for growth in later years, robbing them of getting as far in life as they would have.
Do we think this is likely? Surely if we also have an incentive that compares schools to each other in terms of their test scores at the same time -- which we currently do now -- then schools could be both incentivized to a) maximize the scores at every grade, and b) increase the scores the most?
Since state standardized tests are now adaptive, there is no reason to have the student who comes in knowing everything at their grade level to appear stagnant in testing. They can test beyond their grade level. That would incentivize schools to do something for those students instead of to ignore them.
I agree gaming the system is always a temptation with accountability systems.
I’m not sure it would work like how you are proposing, since purposely stunting a student would penalize the school exactly as much as they would “gain” as the student catches back up.
By rewarding growth, schools are incentivized to prevent earlier grades from doing too well.
One student with potential pushing the overall performance higher than that school might like for that year might be purposefully stunted in order to allow room for growth in later years, robbing them of getting as far in life as they would have.