Friday, March 18, 2011

The Mystery of the High School Graduate

This is not a rant against the educational system or teachers. It is a rant against the morons who presume to "measure" their success with the so-called "averaged freshmen high school graduation rate." This rate makes headlines in every local newspaper across the country, purporting to show how poorly local schools are performing. Nationally, the rate was 74.9 percent in 2007-08 (the latest data available)--which is interpreted by the news media and by many experts who should know better to mean that only 74.9 percent of American children graduate from high school. The rate varies widely by state, from a low of 51.3 percent in Nevada to a high of 89.6 percent in Wisconsin.

You probably think this rate is calculated as it should be--by tracking individual high school freshmen and determining how many eventually graduate from high school. You would be wrong. It is calculated by the National Center for Education Statistics this way: headcount of high school graduates in a given year divided by headcount of freshmen in the school district four years earlier. 

Do you see the problem here? Students who move out of a school district or even transfer to a local private school become "dropouts." Students who get their GED rather than a high school diploma are "dropouts." Students who are held back a year for whatever reason are counted as "dropouts." This explains why states with high levels of migration (Nevada) have lower graduation rates than states with little migration (Wisconsin). The resulting "graduation rates" that make headlines--and bring the wrath of taxpayers down on their local schools--have nothing to do with the success or failure of schools and everything to do with broader demographic trends.

The National Center for Education Statistics also calculates high school completion rates another way, a way that actually measures educational success. Using data from the Current Population Survey, the NCES statisticians calculate the percentage of people aged 16 to 24 who have a high school diploma or GED (see table here). By this calculation, 89.9 percent of the age group had completed high school in 2008--an all time high.  

No comments: