Various measures have been developed to provide information about student persistence and progress through formal elementary and secondary education. Three measures are presented in this report: the status dropout rate (indicator 23), the public school averaged freshman graduation rate (indicator 21), and the educational attainment of 25- to 29-year-olds (indicator 25). The three indicators in this volume that present these measures each employ a different analytic method and dataset to document a different aspect of the complex high school graduation and dropout process. No one data source provides comprehensive information on the graduation and dropout process on an annual basis, but the three indicators presented here complement one another and draw upon the particular strength of their respective data. Each indicator is not without its limitations, however, which makes it critical to have multiple indicators when addressing the question of student persistence. A brief description of the relevant methodology and data used by each indicator follows.

The reader should note that for indicator 22, students with disabilities exiting high school with a regular diploma, the Office of Special Education Programs (OSEP) calculates the “graduation rate” for students with disabilities by dividing the number of students age 14 or older who graduated with a regular high school diploma by the number of students in the same age group who are known to have left school (i.e., graduated with a regular high school diploma, received a certificate of completion, reached a maximum age for services, died, moved and are not known to be continuing in an education program, or dropped out). This percentage should not be confused with other graduation rates reported by NCES in this volume and elsewhere because it is based only on those students leaving school. It does not account for students who remain in school nor does it follow a specific cohort over time. For more information, see supplemental note 8 on student disabilities.

STATUS DROPOUT RATE

Indicator 23 reports status dropout rates by race/ethnicity. Status dropout rates measure the extent of the dropout problem for a population and as such can be used to estimate the need for further education and training in that population. This indicator uses October Current Population Survey (CPS) data to estimate the percentage of the civilian, noninstitutionalized population ages 16 through 24 who are not in high school and who have not earned a high school credential (either a diploma or an equivalency credential such as a General Educational Development [GED] certificate), irrespective of when they dropped out. An advantage of using CPS data to compute this status dropout rate is that the rate can be computed on an annual basis for various demographic subgroups of adults and can be used to report a national rate that includes dropouts of public and private schools. The disadvantages of using CPS data to compute status dropout rates are that they (1) exclude all military personnel and incarcerated or institutionalized persons and (2) include as dropouts individuals who never attended U.S. schools, including immigrants who did not complete the equivalent of a high school education in their home country.

PUBLIC SCHOOL AVERAGED FRESHMAN GRADUATION RATE

Indicator 21 examines the percentage of public high school students who graduate on time by using the averaged freshman graduation rate (AFGR). The AFGR is a measure of the percentage of the incoming freshman class that graduates 4 years later. The AFGR is the number of graduates with a regular diploma divided by the estimated count of incoming freshmen 4 years earlier as reported through the NCES Common Core of Data (CCD), the survey system based on state education departments’ annual administrative records. The estimated count of incoming freshmen is the sum of the number of 8th-graders 5 years earlier, the number of 9th-graders 4 years earlier (because this is when current year seniors were freshmen), and the number of 10th-graders 3 years earlier, divided by 3. The intent of this averaging is to account for the high rate of grade retention in the freshman year, which adds 9th-grade repeaters from the previous year to the number of students in the incoming freshman class each year. Enrollment counts include a proportional distribution of students not enrolled in a specific grade. An advantage of using CCD data to calculate the AFGR is that they are available on an annual basis by state; however, the demographic details are limited.

EDUCATIONAL ATTAINMENT OF 25- TO 29-YEAR-OLDS

Indicator 25 examines the educational attainment of adults just past the age when most would traditionally be expected to complete their postsecondary education. This indicator uses March CPS data to estimate the percentage of civilian, noninstitutionalized people ages 25 through 29 who are out of high school and who have earned a high school credential (either a diploma or an equivalency credential such as a GED); the rate can be reported by race/ethnicity and other demographic variables. The rate does not differentiate between those who graduated from public schools, who graduated from private schools, or who earned a GED. The rate also includes individuals who never attended high school in the United States. An advantage of using CPS data to compute the educational attainment rate is that the rate can be computed on an annual basis for various demographic sub-groups of adults and can be used to report a national rate that includes public and private schools. A disadvantage of using CPS data to compute the educational attainment rate is that these data exclude all military personnel and incarcerated or institutionalized persons.

Even though indicators 21, 23, and 25 document different aspects of student persistence, a number of important differences between these indicators should be noted and recognized as likely factors responsible for the divergence between their respective estimates. General differences can be found in the population of interest, information source, and data collection time frame. For example, the three indicators mentioned above focus on different populations: indicator 23 focuses on 16- through 24-year-olds between 1972 and 2005; indicator 21 focuses on the number of graduates in 2003–04 based on the 2000–01 freshman class; and indicator 25 focuses on 25- through 29-year-olds between 1971 and 2006. The source of information used to construct the indicators also varies. Indicator 21 is produced from the CCD, a universe survey system based on state education departments’ annual administrative records, while indicators 23 and 25 use data from the CPS, a sample survey of the civilian, noninstitutional population.

Given such differences, one would not expect to see identical or even similar estimates. In fact, very reasonable differences should be apparent. For example, if one estimate measures only regular diplomas completed on time, it should be smaller than one that is constructed to measure both regular diplomas and GEDs. Once accounting for these methodological differences, the divergence between estimates tends to be in the correct direction and of the right magnitude.

This supplemental note is intended to provide only a brief overview of some of the commonly available data that address the complex issue of high school completion. For more detail on methods used to analyze dropout and graduation rates in these indicators and other related measures of student persistence and progress, see supplemental notes 2 and 3 and the publications by Seastrom et al. (NCES 2006-604; NCES 2006-605) and Laird, DeBell, and Chapman (NCES 2007-024).