FRANKLIN—Franklin and Southampton public school systems fail to graduate almost half of the students who enter their high schools in the ninth grade, according to a study released by the Editorial Projects in Education Research Center.

For every 100 students in Southampton County’s 9th-grade class, only about 51 will go on to earn a diploma, statistics revealed. Franklin eventually graduates about 57 percent of its freshman class, and Isle of Wight schools award diplomas to just over 71 percent of their high school students, the data showed.

The results of the “Diplomas Count 2008: School to College” study were published last week in a report by Education Week magazine. The study was conducted by the national education publication, along with the Editorial Projects in Education Research Center, with support from the Bill & Melinda Gates Foundation.

The research group used a “cumulative promotion index” to calculate graduation rates.

“The CPI represents graduating from high school as a process rather than a single event,” according to a fact sheet released along with district-level data from school systems across the nation.

The index uses data from the U.S. Department of Education’s annual census of public schools and school districts to measure the grade-to-grade promotions and diploma counts in nearly all of the nation’s public schools.

By multiplying grade-specific promotion ratios together, the CPI estimates the likelihood that a 9th grader will complete high school on time with a regular diploma, researchers explained.

According to 2005 data, about 71 percent of 9th graders nationwide graduate four years later. Virginia’s calculated graduation rate is slightly higher, at 72.9 percent.

See Friday’s print edition of The Tidewater News for more on this story.