There is no more widely and confidently held belief about the Arizona public school system than that it has one of the highest dropout rates in the country.
A recent study by the Manhattan Institute, however, indicates that isn't true.
Researchers Jay Greene and Marcus Winters determined the high school graduation rate for the nation and the states for the class of 2003, the most recent year for which a count is available of diplomas actually issued. They calculated the number of freshmen in each state four years earlier and, with a tweak here and there, compared that with the number of diplomas subsequently issued.
According to this report, Arizona actually had a graduation rate slightly above the national average: 71 percent for Arizona compared with 70 percent for the nation as a whole.
Results among the states were skewed toward the top, so Arizona ranked 30th among the states, even though its graduation rate was above the national average.
Still, most people would regard 30th as in the middle of the states, not at the bottom, as is almost universally perceived.
This cohort analysis approach is also used by Education Week for its widely used "Quality Counts" annual report. Education Week uses a somewhat different approach to calculating the freshman number and its most recent report looks at the 2002 graduating class.
It has Arizona's graduation rate at slightly below the national average - 66 percent in Arizona compared with 69 percent for the nation as a whole. Nevertheless, that put Arizona 35th among the states, again not the bottom-dwelling status universally believed.
Arizona also supposedly does a uniquely lousy job of graduating Latino students. "Quality Counts," however, calculates Arizona's graduation rate among Latinos at slightly above the national average -57 percent in Arizona compared with 55 percent for the nation as a whole.
So, where does the nearly universal belief come from that Arizona has one of the highest dropout rates in the country?
Primarily, it comes from studies relying on self-reported educational attainment in population surveys, rather than from any analysis of the performance of students who have actually been in Arizona schools.
The Annie E. Casey Foundation's "Kids Count," for example, measures the dropout rate for states by the percentage of young people age 16 to 19 who, according to the Census Bureau, don't have a high school degree and aren't in school. By that measure, Arizona has the fourth-highest dropout rate in the country.
But, according to that methodology, a 19-year-old without a high school education who came from another state or Mexico to Arizona to work is considered a dropout from Arizona schools, even though he never spent a day in an Arizona classroom.
The National Center for Education Statistics looks at a broader age range, 18- to 24-year-olds, but also relies on self-reporting on population surveys. In that age segment, Arizona does have the lowest percentage with a high school education in the country. But, again, there is nothing that correlates that population with time spent in Arizona schools.
Another commonly cited source is self-reported graduation rates by the states as part of the No Child Left Behind Act. Arizona has the fifth-lowest self-reported graduation rate.
There are, however, no standards for such reporting. Arizona uses a cohort analysis approach comparable to that used by the Manhattan Institute and for "Quality Counts." Most states do not. So, Arizona is being penalized for honesty.
In reality, what is unknown about Arizona's true dropout problem - kids who actually spend time in Arizona classrooms - vastly exceeds what is known.
For example, Gov. Janet Napolitano often claims that her all-day kindergarten proposal will reduce Arizona's allegedly high dropout rate. Advocates for preschool education are making the same claim about their initiative to fund such programs through an increase in the tobacco tax.
Both claims, however, assume that the kids who are dropping out are in Arizona at such young ages. In reality, however, no one knows when kids who are dropping out entered the Arizona school system, nor what the dropout rate is among those who have spent their entire school career in Arizona schools. If kids who are dropping out tend to enter the Arizona school system in later years, these proposals will have little effect on the dropout rate.
None of this is to say that Arizona should be indifferent to the dropout issue. In fact, the implication of the Manhattan Institute's study is that, nationally, the high school dropout problem is even worse than commonly perceived. Real graduation rates, looking at actual students moving through the system, are substantially below self-reported educational attainment in population surveys.
While Arizona does not appear to do a substantially worse job in graduating Latinos than other states, every study indicates that they graduate from high school at a substantially reduced rate. Since Latinos are a higher percentage of students in Arizona than elsewhere, it's a greater and more important challenge here.
Doing better, however, begins with reality. And the best evidence is that, despite the nearly universal acceptance of the claim, Arizona's public school system does not have one of the highest dropout rates in the country.