Texas this week announced a state takeover of the Houston public school district, the state’s largest and the eighth-largest in the country, a controversial move that will replace its democratically elected school board and superintendent with a board of managers appointed by the Texas Education Agency.

While the announcement leaves many unanswered questions about what the takeover will mean for the district’s roughly 200,000 students, education experts told NBC News that research on previous district takeovers has shown no significant gains in student performance, and even some declines.

“We find no evidence that on average that takeovers improve academic achievement and found evidence that it can be kind of disruptive on average in the early years,” said Beth Schueler, an assistant professor of education and public policy at the University of Virginia.