How Does the EPE Research Center Calculate Graduation Rates?
Diplomas Count uses the Cumulative Promotion Index (CPI) method to calculate high school graduation rates for American public schools. This approach allows the EPE Research Center to compute the percent of public high school students who graduate on time with a diploma.
The CPI method represents the high school experience as a process rather than an event, capturing the four key steps a student must take in order to graduate: three grade-to-grade promotions (9 to 10, 10 to 11, and 11 to 12) and ultimately earning a diploma (grade 12 to graduation). Each of these individual components corresponds to a grade-promotion ratio. Multiplying these four grade-specific promotion ratios together produces the graduation rate.
Different methods for calculating a graduation rate may employ different definitions of a “graduate.” The CPI method adheres to the guidelines established under the federal No Child Left Behind Act, by counting only students receiving standard high school diplomas as graduates. Recipients of General Educational Development diplomas, certificates of attendance, and other nondiploma credentials are treated as nongraduates in this context. States are likewise mandated to adopt a similar definition of a graduate for the rates they calculate for adequate yearly progress (AYP) under the federal law (although they may adopt different definitions for other purposes).
The 2010 edition of Diplomas Count presents a new analysis of graduation rates for the high school class of 2007, the most recent year for which information is available. Data for 2007 and prior years were obtained from the U.S. Department of Education’s Common Core of Data (CCD). The CCD, an annual census of all public schools and school districts in the country, also provided the data on district characteristics used in this report’s analyses of expected graduation rates.
The District of Columbia, Kentucky, and Oregon did not report 2006-07 diploma counts for student subgroups to the CCD. The EPE Research Center was able to obtain additional graduation data directly from the state education agencies of Kentucky and Oregon.
The EPE Research Center calculates graduation rates for all school districts in the country that issue diplomas (that is to say, those with a 12th grade). Statistics for the nation and states are generated by aggregating district-level data upward.
Vol. 29, Issue 34, Page 30Published in Print: June 10, 2010, as How Does the EPE Research Center Calculate Graduation Rates?