Student-teacher ratios at K12, the nation’s largest online educator, are nearly twice as high as Florida’s state-run virtual school, according to internal company documents obtained by the Florida Center for Investigative Reporting and StateImpact Florida.

A high school teacher working for K12 may have as many as 275 students, compared to Florida Virtual School, which has a maximum class size of 150.

“The concept of one teacher managing 275 or 300 students -- it just doesn’t make sense,” said Luis Huerta, a Columbia University education professor who studies online education. “It’s hard to believe one person could do that. You have teacher-pupil ratios that are ten times what it would be in a traditional school.”

According to company documents, K12 provides better student-teacher ratios to schools that pay more per student, though even the best ratios are higher than the state-run competitor’s.

The publicly traded K12 operates in 43 Florida school districts, including in Miami-Dade, Broward, Hillsborough, Orange and Duval counties, with students ranging in education level from kindergarten to high school.

K12 has come under fire for high student-teacher ratios and poor student performance in Arizona, Georgia and Tennessee. A July 2012 study by the National Education Policy Center at the University of Colorado found that K12’s students fell further behind in reading and math scores than traditional students.

The online educator is now under investigation by the Florida Department of Education for allegedly using improperly certified teachers and asking employees to cover up the practice.

Better Pay, Better Ratio

K12’s executive vice president of school services, Chip Hughes, laid out the company’s class-size formula in a confidential April 2010 memo.

Under the formula, the more a school district pays, the better the student-teacher ratio.

School districts that pay $4,000 or more per student receive a 225-to-1 student-teacher ratio in high school classes. Districts paying less than $3,000 per student have a 275-to-1 ratio.

By contrast, Florida Virtual Schools, a state-run competitor to K12, uses a maximum ratio of 150-to-1. Florida’s Class Size Amendment, which does not govern online education, allows for a maximum of 25 students per classroom.

Asked if the ratios in the internal company memo are accurate, K12 spokesman Jeff Kwitowski said in a statement: “As with traditional schools, it varies by school, grade and course.”

No industry standard exists for student-teacher ratios in online education -- the field is still new and little research is available. But education experts believe teacher involvement with students has the greatest effect on academic achievement.

K12 contracts with local school districts to provide virtual education to students throughout Florida. The for-profit online educator does not report student-teacher ratios to local school districts, and public school administrators have no way to audit a teacher’s student load independently, since one K12 teacher could have students scattered around the country.

State Investigation

Earlier this month, FCIR and StateImpact Florida revealed an ongoing state investigation of K12 involving teacher certification.

The state Department of Education’s Office of Inspector General, prompted by school officials in Seminole County, is examining whether K12 uses improperly certified teachers, in violation of state law. K12 allegedly asked certified teachers to sign for having taught students they never encountered, according to documents that are part of the investigation.