In 2004, researchers at Johns Hopkins University released a controversial study identifying hundreds of U.S. high schools as "dropout factories."

At that time, Doctors Robert Balfanz and Nettie Letgers named 32 Washington state schools as having graduation rates of less than 60 percent. They drew a lot of heat as administrators took issue with their findings.

Last fall, that report was updated to include figures for the 2007-2008 school year. It touted a decline in the number of schools producing the greatest number of dropouts. When that study came out, researchers promised they would release the names of the schools on their list this month.

Well, the follow up to that study, "Building a Grad Nation," was released this week. The report indicates the number of dropout factories in Washington increased from 23 to 24 between 2008 and 2009, one of only nine states in the country to show an increase. But, researchers are still withholding the names of those schools.

I spoke with Dr. Balfanz' office Thursday morning to ask why. The bottom line - they're just not saying. One could theorize that they don't want to deal with the criticism they got after the 2004 report.

At the heart of that criticism is the ongoing debate in education circles on how to calculate dropout statistics. If you look at the Office of Superintendent of Public Instruction's website you'll find a glaring discrepancy between the graduation grate, the extended graduation rate and the dropout rate. The numbers don't add up.

For example, if you look at the OSPI website it shows the class of 2009 had a graduation rate of 73.5 percent. The extended graduation rate (in which students were given a fifth year to graduate) increased to 79.2 percent. At the same time, the state's dropout rate is listed as only 5.1 percent.

The state determines that dropout rate on what's called an "annualized" figure based on the number of high school seniors who start the year minus the number of seniors who failed to complete the grade. That method fails to take into account the vast number of children who drop out in their freshman, sophomore and junior years.

If you calculate the dropout rate on what's called a cohort of cumulative basis, the rate jumps to more than 20 percent. OSPI is slated to release graduation statistics for the class of 2010 in the next few weeks.

In a conversation with Dr. Balfanz last November, he said, "Most dropouts don't bother dropping by the principal's office to say goodbye." He acknowledges what he measures is a school's "promotion power" -- comparing the number of freshmen at a school to the number of seniors at the same school four years later.

This is the first year that all states, all districts and all schools are required by law to calculate graduation rates based on a common formula. It will be interesting to see how that changes the information we are provided by OSPI and Johns Hopkins.