This study appears to want to prove racism is the driving factor for higher school-discipline rates for minorities. Do you believe lack of racism ensures life success? Just look at depressed, mainly white communities.
Why not look for other causations than racism? Why not also study disparities in students' response to school authority? Why not try to correlate incidents to one-parent households? Most successful students get encouragement from home, like I did. Why not try to correlate to that? Why not correlate to social promotion? Or basic living needs being met? Perhaps talk with successful black people for their opinions on your study design, like Dr. Ben Carson and Condoleeza Rice.
Good luck getting truthful interviews from school personnel.
We saw how dangerous outcome-based discipline can be, and any study that recommends it. Recall that the Parkland, Fla., shooter was noted to have extreme prior behavior. It wasn't addressed while he was in school, due to Obama-era federal school-discipline regulations which no bureaucrat would deem subordinate to better judgment.