In the controversial documentary on American education, Waiting for Superman, director Davis Guggenheim (An Inconvenient Truth) brings up various statistics to prove that American schools are failing.

The title of the film suggests America is waiting for a hero to come fix the broken school system. But in the film Guggenheim advocates that a “hero” has already arrived in the form of charter schools.

Two charter school programs in particular, the Knowledge is Power Program nationally and Geoffrey Canada’s Harlem Children’s Zone in New York City, are portrayed as the epitome of academic success. While Guggenheim says only one in five charter schools is highly successful, he only focuses on KIPP and Harlem Children’s Zone schools.

A 2003 study by the National Assessment of Educational Progress, however, found that fourth-grade students in charter schools scored lower than their non-charter peers in both math and reading. The NAEP is part of the U.S. Department of Education.

“The average charter school mean was 5.2 points lower than the average public non-charter school mean,” the report stated on reading scores. “After adjusting for multiple student characteristics, the difference in means was 4.2 points. Both differences were statistically significant.”

And yet charter schools are undeniably a growing trend in the U.S. According to the National Center for Education Statistics, the number of students enrolled in charter schools has more than tripled in the last 10 years.

The racial makeup of charter schools has also shifted, as might be assumed from the portrayal of the students in Waiting for Superman. Of the five students followed throughout the film, one is white and the others are black or Hispanic. The national center’s report stated that, “In 2007-08, about 26 percent of charter schools had student populations that were more than 50 percent black, compared to 17 percent of all public schools.”

As other ways to highlight the failures of the American public school system, Guggenheim points to the United States ranking among other countries and dropout rates in high schools. Guggenheim says that among 30 countries, the U.S. ranks 25th in math and 21st in science. But data from the National Center for Education Statistics puts the U.S. in the middle of the Group of eight countries in terms of math literacy and near the top in science.

In the short promotional film for the documentary, production company Buck Studios uses an onslaught of statistics from the movie to explain the plight of the high school dropout.

Akash Tharani, a high school Teach for America teacher in Chicago, said he heard the film left some parts of the issue out, so he would be cautious in his takeaway.

“I think you leave feeling like you want to do something,” Tharani said, “but in some way I feel like things are oversimplified.”