These are the kids you can least afford to fail. It's like having a fast progressing cancer. You have to try a lot of things because the alternative is so bad.
The solution to improving the outcomes for these kids doesn't start at school, it has to start at home.
This is not true.
The Gates Foundation, whom I generally dislike quite intensely for being busybody carpetbaggers who muck things up and disappear, documented this all very well. 2 teachers and 15 students per class works. Period. Every single program that did this showed significant improvements with the most improvement in the lowest performers.
The biggest problem, of course, is that when you ask for money for 2 teachers per 15 students everybody loses their minds (except the rich, of course, who understand the correlation perfectly). Every single one of the programs that the Gates Foundation documented as working were eventually shut down because of lack of funding.
People only say they want better education. Their actions say otherwise.
While this is fine in elementary and early middle school (which is where the Gates foudnation documented), this probably breaks down as you enter high school where teachers need to be specialized and you need to have a pool of teachers to cover all subjects.
The US is one of the wealthiest countries in the world, we can figure this out.
The problem is that those same students lose terribly over the summer break. Students from better socioeconomic strata gain over the summer break while those of lower socioeconomic strata do not. Thus, when the school year begins again, any gains made over the school year have been more than cancelled out over the summer.
This is one of the big arguments for year-round school.
In addition, higher socioeconomic status children keep making progress during the summer.