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Appendix B: Detailed Methodology for Calculation of Four-Year On-Time Graduation Rates and Event Dropout Rates

The Adjusted Cohort Graduation Rate (ACGR)

Starting with the school year (SY) 2011-12 collection, the ACGR has been and will continue to be included as a required component of each state's Consolidated State Performance Report (CSPR).1 The ACGR is calculated based on the number of students who graduate in 4 years or less with a regular high school diploma divided by the number of students who form the adjusted cohort for the graduating class. In order to calculate and report the 4-year ACGR states must follow the progress of each individual 9-12 grade student over time and maintain documentation of students who enter or leave schools or districts within their state. From the beginning of ninth grade (or the earliest high school grade) students who are entering that grade for the first time form a cohort that is "adjusted" by adding any students who subsequently transfer into the cohort from another state and subtracting any students who subsequently transfer out, emigrate to another country, or die.

The following formula provides an example of how the 4-year adjusted cohort graduation rate would be calculated for the cohort entering 9th grade for the first time in SY 2008-09 and graduating by the end of SY 2011-12:

Number of cohort members who earned a regular high school diploma by the end of SY 2011-12
Number of first-time 9th-graders in fall 2008 (starting cohort) plus students who transferred in, minus students who transferred out, emigrated, or died during school years 2008-09, 2009-10, 2010-11, and 2011-12

State education agencies (SEAs) report ACGR data for each school, LEA, and for the state total cohort rate. The methodology of the ACGR, as it was designed, allows for the movement or transfer of students from one school to another, while only counting each student once. A student may change schools and thus exit their prior school's cohort and enter their new school's cohort, but stay in the same district and state cohort. Similarly, a student who changes districts within a state will move to the new school and district for the ACGR, but will stay in the states cohort. In order to subtract or transfer a student out of a cohort, the school or LEA must have official written documentation that the student enrolled in another school or in an educational program that culminates in the award of a regular high school diploma.

Unless specified, the ACGR data in this report and the associated data files reflect the data as reported by each SEA. The ACGRs required under the current Title I regulations are more comparable across states than were graduation rates submitted by SEAs under prior regulations. However, there has been some variation in the way that individual states have interpreted and understood the methodology specified in the statute. Examples of ways the calculated ACGR may vary among states include

  • how students are identified for inclusion in certain subgroups;

  • how the beginning of the cohort is defined;

  • whether summer school students are included; and

  • the criteria of what constitutes a diploma that meet the regulatory definition of a regular high school diploma.2

SEAs report the ACGR disaggregated by major reporting groups. The specific groups vary across states depending on the relative size of certain disaggregation populations of interest and the subgroups they have been approved to report as part of their CSPR Accountability Workbooks. For the purpose of this report, data have been aggregated to five race/ethnicity subgroups: American Indian/Alaska Native, non-Hispanic; Asian/Pacific Islander, non-Hispanic; Hispanic; Black, non-Hispanic; and White, non-Hispanic. Additional levels of disaggregation may be presented in other reports and/or data files associated with the ACGR.

Detailed information on the ACGR can be found in the Department's 2008 High School Graduation Rate Non-Regulatory Guidance:

Detailed information on the guidance provided to SEA coordinators for submitting data relating to the ACGR can be found in the EDFacts file specifications 150 and 151. Links to both file specification documents can be found on the EDFacts File Specification website:

The Averaged Freshman Graduation Rate (AFGR)

The AFGR provides an estimate of the percentage of high school students who graduate within 4 years of first starting 9th grade. The rate uses aggregate student enrollment data to estimate the size of an incoming freshman class and counts of the number of diplomas awarded 4 years later. The incoming freshman class size is estimated by summing the enrollment in 8th grade in year one, 9th grade for the next year, and 10th grade for the year after, and then dividing by three. The averaging has a smoothing effect that helps compensate for prior year retentions in the 8th-, 9th-, and 10th-grade enrollment counts. Although not as accurate as a 4-year graduation rate computed from a cohort of students using student record data like the ACGR, the AFGR can be computed with widely available cross-sectional data. Based on a technical review and analysis of several 4-year graduation rates, the AFGR was selected as the most accurate indicator, excepting only the ACGR, from a number of alternative estimates that can be calculated using available cross-sectional data (Seastrom et al. 2006a, 2006b).

The following formula provides an example of how the AFGR would be calculated for the graduating class of 2011:3

Number of regular high school diplomas awarded in SY 2010-11
The number or 8th-graders enrolled in the fall 2006 plus
the number of 9th-graders enrolled in the fall 2007 plus
the number of 10th-graders enrolled in the fall of 2008) divided by 3

The AFGR was intended to address a lack of regular information about timeliness of graduating from public high schools. Precise measures of how long it takes for a student to graduate high school require data sources that follow the progress of each individual student over time. Until recently, most states lacked data systems that captured individual public-school student-level data over time. The AFGR was developed to utilize data that were available across the 50 states on a regular basis to provide a general and comparable measure of the percentage of public high school students who graduate with a regular high school diploma within 4 years of first entering 9th grade. The AFGR is useful for longitudinal analysis of graduation rates since the data used to generate the AFGR are available going back in time to at least the 1960s.

The levels of disaggregation for the AFGR components are complicated by the different years for which data are necessary in the computation of the rate. Prior to the SY 2008-09 collection, enrollment and graduation data were collected disaggregated by 5 major racial/ethnic groups: American Indian/Alaska Natives, Asian/Pacific Islanders, Hispanics, Blacks, and Whites. The reporting of Hawaiian/Pacific Islanders disaggregated from Asian/Pacific Islander students and the separate reporting of students of more than one race was phased in for SY 2008-09. For SY 2008-09 seven states reported students disaggregated into the seven race/ethnicity categories. For SY 2009-10 eight additional states reported at that level of disaggregation. By SY 2010-11 all states were required to report by the seven race/ethnicity categories rather than the traditional five.4 Because the SY 2010-11 AFGR calculations require data going back to SY 2006-07 it is only possible to calculate it by the collapsed five race/ethnicity categories. Thereby, these five categories are the only levels of disaggregation available in this report and in the associated data files.

Detailed information on the guidance provided to SEA coordinators for submitting data relating to the AFGR can be found in the EDFacts file specifications. Links to both file specification documents can be found on the EDFacts File Specification website:

Differential Definitions for "Regular High School Diploma Recipient"

State and local policies can affect the numbers of regular high school diploma recipients (REGDIP) reported. There are differences in what a regular high school diploma represents across states. EDFacts file specifications for both annual and cohort REGDIP define a regular diploma as the high school completion credential awarded to students who meet or exceed coursework and performance standards set by the state or other approving authority. While this language provides a definition of common intent, the requirements required to earn a high school diploma varies among states. States therefore have differing requirements for REGDIP in terms of required attendance, coursework requirements (Carnegie Units), and exit exams.

High School Event Dropout Rate

In calculating the event dropout rate, high school dropouts for a given school year include students who were

  • enrolled in school at some time during the school year;

  • expected to be in membership the following school year; and

  • not enrolled in grades 9-12 in by October 1 of the following year.

Dropouts do not include students who were

  • reported as a dropout in the year before;

  • among students who graduated high school by completing the state graduation requirements, receiving a high school equivalency credential without dropping out of school, or completing a
    state or district-approved educational program;

  • confirmed as having transferred to another public school district, private school, or state or district-approved educational program;

  • temporarily absent due to suspension or illness; or

  • deceased.

The high school event dropout rate is the number of dropouts divided by the number of students enrolled in grades 9-12 at the beginning of that school year. In cases where LEAs or SEAs report students and dropouts in an ungraded category, the National Center for Education Statistics (NCES) prorates ungraded students and dropouts into grades in order to calculate an aggregated dropout rate for 9th- through 12th-grade students.

Not all states follow a fall-to-fall school year. The Common Core of Data (CCD) dropout count is based on an October-September school year in which a student's dropout status is determined at the beginning of the year. Some states follow a July-June calendar in which a student's dropout status is determined at the end of the school year. Dropout rates in states that follow an alternative reporting calendar are comparable with rates for states that follow the October-September calendar (Winglee et al. 2000) and are included in the CCD data files.

The CCD definition attributes dropouts to the grade and school year for which they do not meet their obligation. Students who complete 1 school year but fail to enroll in the next school year are counted as dropouts from the school year and grade for which they failed to return. For example, a student completing 10th grade in SY 2008-09 who does not enroll the next year would be reported as an 11th- grade dropout for SY 2009-10.

Students who leave high school to enroll in high school equivalency preparation programs are reported as dropouts, unless the district tracks these students and reports as dropouts those who fail to complete the program. If a high school equivalency program is an accepted high school credential in the state's Data Usage and Availability, students who have received a high school equivalency by October 1 are not considered dropouts, regardless of where they prepared for the test.

These data are released to the public and to IES Restricted-Use Data Licensees. Public release files can be obtained through

  • the CCD website (ACGR and AFGR data);

  • the Office of Elementary and Secondary Education (OESE) website (ACGR state-level data); and

  • the DATA.GOV initiative (ACGR school- and LEA-level data).

Public release data include graduation and dropout rates by race/ethnicity and other demographic characteristics at the school district, and state levels.

For more information on the information available on the public-use data files, please visit the CCD data file download page at, the OESE data tool at, and the government-wide DATA.GOV initiative at:

To learn more about restricted use data files or how to apply for an IES Restricted Use Data License, visit the Restricted Use Data License page at: or contact the IES Restricted Use Data License Office at:

Ensuring Confidentiality of Individual Student Data

The Department of Education is legally required to protect the confidentiality of data that could be used to identify individual students. Legal requirements for protecting the data are detailed in the Family Education Rights and Privacy Act (FERPA) (20 U.S.C. § 1232g; 34 CFR Part 99). FERPA requires that these data be protected to ensure they cannot be used to identify the attributes of any individual student. Beyond the natural barriers to precise identification, including differential time frames and net transfer effects, additional disclosure mitigation methods have been applied to these data to ensure confidentiality.

Beginning with the SY 2010-11 graduation and dropout data, NCES' public release files will only include rates or ranges of rates. Explicit counts of graduates and dropouts will only be available on the restricted-use files for each of the state, LEA, and school levels. The Department of Education's Disclosure Review Board has established a set of mandatory procedures for these data to protect the confidentiality of individual student data. The procedures establish rate floors (minimums) and ceilings (maximums) based on the size of the population being examined. Small populations require more protection at the top and bottom of the distribution than do large populations to achieve the same level of confidentiality protection. For the public-use, LEA-level files, rate ranges within the distribution have also been established. These ranges are based on the same methodology as the floors and ceilings established for SEA-level data. Making the floors, ceilings, and ranges dynamic based on population size allows these rates to be published at a maximum level of precision allowable for a specific measured population.

NCES makes restricted-use data files available to researchers through IES Restricted-Use Data Licenses. Restricted use data files of administrative data have not undergone data coarsening. Licensees with access to these restricted use data must sign an agreement to ensure that any data disseminated outside of the authorized research team are protected using the Department of Education approved disclosure avoidance methodology for the licensed data set to ensure the confidentiality of individual student data. Any public releases of these data, including presentation materials, journal articles, website postings, etc. must be reviewed by IES to ensure that the Department of Education's approved disclosure avoidance methodology has been employed prior to release. The researchers and the sponsoring organizations are held accountable for any and all failures to comply with the strict requirements agreed to within the IES Restricted Use Data License agreement. Data confidentiality violations by IES Restricted Use Data Licensees are subject to Class E felony charges, with a fine up to $250,000 and/or a prison term up to 5 years.