Washington (CNN) -- Class size and what it means to how kids learn has been a long and hotly contested issue. President Barack Obama and many educators believe smaller classes, with fewer students per teacher, are the way to go.
So Obama's latest ad tries to school Mitt Romney on that subject.
"Some of our children's greater experiences have been in smaller classrooms ... but Mitt Romney says class sizes don't matter, and he supports Paul Ryan's budget, which could cut education by 20 percent," the ad says.
But did Romney really say class sizes don't matter?
The answer is no.
Talking to a group of Philadelphia teachers in May, Romney said, "If you had a class size of five, that would be terrific. If you have a class size of 50, that would be impossible."
But Romney cited a McKinsey Global Institute study that showed sometimes, schools with small classes fail, and sometimes, schools with big classes succeed. Therefore, he said, class size should not be given excessive weight in efforts to improve schools.
You would expect Obama's education advisers to disagree with that notion, but they don't.
Class sizes might matter up to third grade, "... But in secondary schools, districts may be able to save money without hurting students, while allowing modest but smartly targeted increases in class size," Secretary of Education Arne Duncan told the American Enterprise Institute in 2010. "In fact, teachers in Asia sometimes request larger class sizes because they think a broad distribution of students and skill levels can accelerate learning."
After our report published, the Department of Education requested that we "clarify" Duncan's position.
Department press secretary Justin Hamilton said in a statement:
"What Secretary Duncan has said is that class size is especially important in the early years and we should focus our class size efforts where the evidence shows it's most effective," it read.
"He's also been clear on the fact that the most important thing we can do for students is have a great teacher in every classroom and that we should pay our teachers like professionals," Hamilton's statement continued.
As for Ryan's plan to cut education funding, the truth is that while education might suffer under a Ryan budget, how much would be cut and where might it be cut from is not clear.
Given the facts, we are tempted to give Obama's ad an "F" for false. But we'll settle on an "M" for misleading.