Appendix B—Methodology

The source of the data for this report is the 2008–09 Common Core of Data (CCD). There are three nonfiscal CCD surveys that collect basic descriptive data on public education in the nation: the school survey (Public School Universe Survey), local education agency survey (Local Education Agency Universe Survey), and state survey (State Nonfiscal Survey). These data are collected through the U.S. Department of Education's Education Data Exchange Network (EDEN) data collection system. Fiscal CCD data are gathered at the state level by the National Center for Education Statistics (NCES) in the National Public Education Financial Survey (NPEFS) and at the local level in the Annual Survey of Local Government Finances (F-33 series of the Census of Local Governments) conducted by the Governments Division of the U.S. Census Bureau. The most recent fiscal year for which data are available is 2008. Puerto Rico fiscal data were taken from the fiscal year 2008 NPEFS.

CCD data are provided by state education agencies (SEAs) from each of the 50 states, the District of Columbia, Puerto Rico, the Bureau of Indian Education, the Department of Defense dependents schools (overseas and domestic), and four outlying areas (American Samoa, Guam, the Commonwealth of the Northern Mariana Islands, and the U.S. Virgin Islands). Data for all of these states and jurisdictions are included in this report. If a data item is marked "data not available," it indicates the state or jurisdiction did not report the data item in its CCD submission.

Districts represented in this report have various sizes and geographic locations. The District of Columbia, Hawaii, and Puerto Rico are each administered as one school district. Some districts comprise a substantial portion of a state's total student membership, while others make up only a small fraction of membership.

Data Quality

CCD data are reported by SEAs for individual schools and districts within the state, as well as for the state as a whole. Staff at NCES and the U.S. Census Bureau work with the SEAs to clean and edit the data. State coordinators correct or confirm any numbers that are challenged in the NCES edits. NCES accepts the states' responses to these edit questions; however, in a limited number of situations, if the SEA does not provide NCES with the explanation or new data for an item, NCES will suppress or edit the data.

NCES challenges SEA data under several circumstances. Some examples of edits include numbers appearing out of range when compared to national averages, the previous year's data, or internal state reports. If a response is logically impossible, NCES will consult with the state and replace the response with a logically acceptable alternative. For example, in the 2008–09 CCD, the following districts reported counts of zero in the following staff categories: Clark County School District, Nevada, and Washoe County School District, Nevada, instructional support staff; and Boston, Massachusetts, library media staff. The states were consulted about these values, and as a result the values were changed to "not available." As another example of an edit, if a reported total is less than the sum of the detail comprising that total, the total will be changed to the sum of the detail. Data may also be adjusted for confidentiality.

Item Nonresponse

Some items were not available for some school districts. The following items describe nonresponse in the CCD school and agency universe surveys that affected the information presented in this report:

  • no data on instructional support staff for Clark County School District, Nevada, and Washoe County School District, Nevada;
  • no pupil/teacher ratio data for other instructional levels for Pinellas, Florida and Fulton County, Georgia;
  • no data on magnet schools for Gwinnett County, Georgia; Mesa Unified District, Arizona; Tucson Unified District, Arizona; Boston, Massachusetts, and Clayton County, Georgia;
  • no data on free and reduced-price lunch eligibility for the Wake County Schools, North Carolina;
  • no other high school completer data for the Detroit City School District, Michigan; the Milwaukee School District, Wisconsin; the Jordan District, Utah; the Greenville 01 district, South Carolina; the Granite District, Utah; the Davis District, Utah; and the Alpine District, Utah; and
  • no dropout data for the Puerto Rico Department of Education.

High School Completers, Grades 9–12 Dropout Rate, and Averaged Freshman Graduation Rate

This report presents counts of high school completers, the grade 9–12 dropout rate, and an averaged freshman graduation rate. The term "high school completer" includes both diploma recipients and other high school completers, but not high school equivalency recipients. The averaged freshman graduation rate only includes diploma recipients; it does not include other high school completers or those receiving a General Education Development (GED)-based equivalency credential.

Diploma Recipients. These are individuals who are awarded, in a given year, a high school diploma or a diploma that recognizes some equivalent level of academic achievement. They can be thought of as students who meet or exceed the coursework and performance standards for high school completion established by the state or other relevant authorities.

Other High School Completers. These individuals receive a certificate of attendance or some other credential in lieu of a diploma. Students awarded this credential typically meet requirements that differ from those for a high school diploma. Some states do not issue an "other high school completion" type of certificate, but award all students who complete school a diploma regardless of what academic requirements the students have met. In order to make data as comparable as possible across states, this report includes both regular and other diploma recipients in its total number of high school completers. High school equivalency recipients are not included.

Exclusion of High School Equivalency Recipients. High school equivalency recipients are awarded a credential certifying that they have met state or district requirements for high school completion by passing an examination or completing some other performance requirement. High school equivalency diplomas are considered valid completion credentials, but high school equivalency recipients are not included in the total number of completers. To ensure data comparability, the CCD publishes state-level data provided by the GED Testing Service.

Grades 9–12 dropout rate. The grades 9–12 dropout rate estimates the percentage of public high school students who left high school between the beginning of one school year and the beginning of the next without earning a high school diploma or its equivalent (e.g., a GED) and do not meet any of the following exclusionary conditions: transfer to another public school district, private school, or state- or district-approved education program; temporary absence due to suspension or school-approved illness; or death. It is calculated by the following method:

dropout rate = number of grade 9-12 dropouts divided by total grade 9-12 enrollment

Ungraded enrollment within each agency is redistributed across other grades in proportion to the graded enrollment.

Averaged freshman graduation rate (AFGR). The averaged freshman graduation rate provides an estimate of the percentage of high school students who graduate on time (i.e., within 4 years of entering 9th grade for the first time). The rate uses aggregate student enrollment data (to estimate the size of an incoming freshman class) and aggregate 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 one year, 9th grade for the next year, and 10th grade for the year after and then dividing by three. The averaging is intended to account for higher grade retentions in the 9th grade compared to 8th and 10th grades. Ungraded students reported to the CCD were prorated into the individual grade enrollment counts. Thus

AFGR equals number of diploma recipients in 2007–08 divided by average 9th-grade enrollment times 100


average 9th-grade enrollment equals 8th-grade enrollment in 2003–04, plus 9th-grade enrollment in 2004–05, plus 10th-grade enrollment in 2005–06

More Information on CCD Methodology

New York City Public Schools, New York. New York did not report the New York City Public Schools as a single district in 2008–09. The state reported a total of 33 geographic districts comprising what had been the New York City Public Schools in previous years. For this report, data for the 33 geographic districts were aggregated to provide data for the New York City Public Schools, New York district. See table D-6 for a list of the 33 geographic districts that comprised the New York City Public Schools district in school year 2008–09.

For more information on CCD universe surveys and response rates, see Numbers and Types of Public Elementary and Secondary Schools From the Common Core of Data: School Year 2008–09 (Chen 2010), Public Elementary and Secondary School Student Enrollment and Staff Counts From the Common Core of Data: School Year 2008–09 ((Sable and Plotts 2010), and Public School Graduates and Dropouts From the Common Core of Data: School Year 2007–08 (Stillwell 2010). These reports discuss missing data and data quality and present state totals for CCD data items from the school, agency, and state surveys. They include state-idiosyncratic treatment of charter and magnet schools as well as schools and districts with no student membership.

Counts of Students with Individualized Education Programs (IEPs), Colorado Districts. Colorado did not report IEP counts for any regular school districts in 2008–09, and therefore did not have IEP counts for any of its districts that are in the 100 largest districts in the United States and jurisdictions. Instead, IEP counts were reported in special administrative unit districts that either represent data for a single regular district or for a collection of small regular districts. For the purposes of this report, the IEP counts reported for the special administrative units determined to be associated with each of the 100 largest school districts that are in Colorado were used as a count of IEPs for that district.

Counts of Students by Race/Ethnicity. Prior to 2008–09, states were asked to report student enrollment counts by five racial/ethnic categories. These categories were (a) America Indian/Alaska Native; (b) Asian/Pacific Islander; (c) Hispanic; (d) Black; and (e) White. Starting with the 2008–09 data collection, states were asked to submit counts of students by race/ethnicity by seven race/ethnicity categories if their state data system allowed for such reporting. These categories are (a) American Indian/Alaska Native; (b) Asian; (c) Hispanic; (d) Black; (e) White; (f) Hawaiian Native/Pacific Islander; and (g) Two or more races. Some states were not able to report their data by the seven racial/ethnic groups, and continued to report their data in the five racial/ethnic groups for 2008–09. In order to increase the comparability of data across states, data for states that reported by 7 racial ethnic groups were collapsed into 6 categories: (a) America Indian/Alaska Native; (b) Asian/Pacific Islander (composed of the categories Asian and Hawaiian/Pacific Islander); (c) Hispanic; (d) Black; (e) White; and (f) Two or more races.