Most school leaders would consider students failing exams to be a bad thing. But the co-founder of one of the most influential school chains in the US has described a recent set of poor results as "great".
Dave Levin, from the widely lauded Knowledge Is Power Program (Kipp) charter schools group, welcomed the fact that New York State had adopted tougher exams, even though it meant that his schools performed badly in them.
Kipp schools, especially those in New York City, have hosted politicians and educationalists from around the world, who are keen to learn the secret of their apparent success with children from challenging backgrounds.
But over the summer, the results of new standardised tests that are closely aligned to the Common Core State Standards - the US attempt to introduce a national curriculum - were published. They showed that all public schools had underperformed.
Charter schools, including Mr Levin's Kipp schools, fared particularly badly in the state-wide assessments. But he was adamant that this was a good thing, because it meant that the tests would better prepare his students for university and the world of work.
"I think it's great that New York has changed the rigour of the tests," Mr Levin told TES. "You can see there is a shift towards the content and skills kids need (for the future).
"And I think what you see is all of the public schools struggled and, by and large, that's why you want that shift because now there is a higher bar that is aligned to college readiness."
The tests were sat by all eight- to 13-year-old students in the state, but less than a third achieved a pass overall. Critics claimed that the poor performance of charter schools, which are publicly funded but independent, meant that they were not the solution to improving standards.
England's education secretary, Michael Gove, has regularly praised Kipp schools and based much of his flagship free schools policy on US charter schools, particularly those operating in New York City.
Mr Levin said the new Common Core State Standards, which have been adopted by 45 states as well as the District of Columbia, would provide a number of benefits, but he warned that many states would struggle.
"I think it's going to be a major shift for teachers, for kids and for families," Mr Levin said. "But I am in favour... It's great that kids in different states are going to be held to the same expectations because, ultimately, it's the United States.
"The fact there will be common assessments really makes sure that we're going to be able to hold ourselves collectively accountable, and we will be able to learn from folks who have really been successful."
But Mr Levin's enthusiasm for the new standards and the tests that come with them is not unanimously shared. Pressure groups and politicians from the Left and the Right have argued that the standards could lead to more high-stakes testing and the state being too involved in education.
Dylan Wiliam, emeritus professor at the University of London's Institute of Education, who sat on the validation panel of the Common Core State Standards, said that the reforms could prove hugely embarrassing for some states.
"When you look at the states in the US, the best outperform Shanghai but the worst underperform Nigeria," Professor Wiliam said. "It will become an inconvenient truth for some when students perform badly."
However, Mr Levin said that this was all the more reason for the new standards to be adopted.
"What happens in public schools too often is kids don't have an accurate reflection of their achievement levels until it's time to apply to college," he said. "They think they're high-achieving but then can't get into university, or need remedial courses once they get there. It's going to be hard and there will be a few years of adjustment. But by doing that earlier, in the long run there will be big gains."