A high school has defended its decision to segregate students by race and gender.
The scheme, at McCaskey East High School in Lancaster, Pennsylvania, separates black students from the rest of the school pupils, and then further breaks it down into black females and black males.
The separation is only for a short period - six minutes each day and 20 minutes twice a month - but it has drawn criticism for raising the spectre of racial segregation.
Today the school's principal defended the policy.
Bill Jimenez said the school noticed that black students were not performing as well as other students, and that research had shown that same-race classes with strong same-race role models led to better academic results.
Mr Jimenez admitted that no other students were divided by race at the school, but he added that academic data dictated the school take a different approach with its black students.
He told Lancasteronline.com: 'One of the things we said when we did this was, "Let's look at the data, let's not run from it. Let's confront it and see what we can do about it".'
The idea came from Angela Tilghman, an instructional coach at McCaskey East.
She said statistics had shown about a third of McCaskey's African-Americans scored proficient or advanced in reading on last year's Pennsylvania System of School Assessment tests, compared with 60 per cent of white students and 42 per cent of students overall.
In mathematics, only 27 per cent of black students scored proficient or advanced.
She said research had shown that grouping black students by gender with a strong role model could boost both academic achievement and self-esteem.
Some students, staff and parents were against the segregation, saying that it ran against everything the school stood for - with students from diverse backgrounds.
But it was something Mr Jimenez thought was worth trying.
In all segregated classes, mentors track their students' grades, test scores and attendance.
One such mentor is Michael Mitchell, who hopes to inspire his black male students during their short daily meetings.
He said he often quoted the Reverend Martin Luther King, who said: 'Nothing in all the world is more dangerous than sincere ignorance and conscientious stupidity.'
Mr Mitchell recently used the quote when he found that some of his students were failing gym.
He said: 'They're all young. They're all strong. They're all athletic. But they're failing because they chose not to participate.
'That's an example of "conscientious stupidity". You can do but you choose not to do. These are the things we need to get away from.