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Appendix A: Methodology and Technical Notes

Common Core of Data survey system. The Common Core of Data (CCD) survey system contains nonfiscal and fiscal components and the Teacher Compensation Survey (TCS). The State Nonfiscal Survey of Public Elementary/Secondary Education, the Local Education Agency Universe Survey, and the Public Elementary/Secondary School Universe Survey are the nonfiscal components, while the School District Finance Survey (F-33) and the National Public Education Financial Survey (NPEFS) are the fiscal components. The TCS is also a part of the CCD survey system.3 State education agencies (SEAs) report these surveys annually to NCES, and participation in the CCD is voluntary.

The U.S. Department of Education collects data for CCD nonfiscal surveys through the EDFacts data collection system. The U.S. Census Bureau performs the data collection for CCD fiscal surveys on behalf of NCES. The Census Bureau collects the fiscal data through an online data collection site. The Census Bureau and NCES then process, edit, and verify the data before publication. The fiscal year 2010 (FY 10) NPEFS collection opened on February 28, 2011, and closed on September 6, 2011. All states, the District of Columbia, Puerto Rico, and the four U.S. Island Areas reported in the FY 10 NPEFS collection.

Data quality. Staff at NCES and the Census Bureau collaborate to edit all CCD data submissions and ask state CCD coordinators to correct or confirm any numbers that appear out of range when compared with other states’ data or with the state’s reports in previous years. If a state provides no explanation for anomalous data, NCES will edit the data value based on a set of defined business rules. For example, NCES will replace a reported total with the sum of detail in cases where the sum of detail exceeds a reported total. NCES will also edit a value to “not available” if data values are not plausible (e.g., if the number of students increases tenfold from the prior year to the current year while the number of teachers remains unchanged from the prior year, NCES will set the current year value for teachers to “not available”).

Missing data. Not all states collect and report all of the data items requested in the CCD surveys. NCES imputes (replaces a nonresponse with a plausible value) for some missing items in NPEFS. Precise information about the extent of missing data is included in the documentation for the NPEFS FY 10 file, which can be accessed at:

Imputed and edited data. NCES imputes and edits some reported values in the NPEFS to create data files that more accurately reflect finance data and to improve comparability among states. Imputations and edits are performed on data from the 50 states, the District of Columbia, Puerto Rico, and the four U.S. Island Areas. A limited amount of data for Guam, the Commonwealth of the Northern Mariana Islands, Puerto Rico, and the U.S. Virgin Islands were reallocated across expenditures functions.

  • Imputations  Imputation is a procedure that uses available information and a set of assumptions to derive substitute values for missing values in a data file (NCES 2003). Imputations modify values for cases or records where data are not reported (missing) or are incorrectly reported. An imputation assigns a value to the missing item using a consistent methodology and increases the subtotals containing this item by the amount of the imputation. The same method is used for imputing revenues and expenditures. Revenues are imputed based on total revenues in reporting states, and expenditures are imputed based on total expenditures in reporting states.
  • Edits correct cases in which a value reported for one item contains a value for one or more additional items not reported elsewhere. For example, a state might not differentiate between instructional support staff and student support staff, reporting “missing” for student support staff salaries and a value for instructional support staff salaries that includes both items. NCES edits these two responses by reducing the amount reported for instructional support staff salaries proportional to prior year data for that state or the averages across states and adding that amount to student support staff salaries. The total for salaries and total expenditures would not be affected by this edit.

All imputed values in the tables in this report are noted. Imputed values are not used in the imputation of other values. Totals and subtotals in tables are noted if one or more items in the total or subtotal are imputed or edited. In some instances, redistribution of reported values to correct for missing data items may affect state values.

Beginning with the FY 06 file, NCES notes values that have been affected by the distribution of state direct support for and on behalf of school districts. This results in many more items having noted data than in previous reports. States that report their direct support expenditures with their detailed finance data are not noted, since no redistribution was required.

Each school year SEAs report student membership counts by grade on the CCD State Nonfiscal Survey of Public Elementary/Secondary Education. The NPEFS data file includes total student membership reported on the State Nonfiscal Survey that includes grades prekindergarten through grade 12 (plus ungraded).  If the reported fiscal data excludes prekindergarten programs, total membership also excludes prekindergarten membership. As part of the FY 10 NPEFS collection process, NCES asked SEAs to review student membership data from the State Nonfiscal Survey and verify that the membership data are consistent with the programs covered in the revenues and expenditures data reported in NPEFS. Three states (Nebraska, Utah, and Wyoming) indicated that the state fiscal data reported in NPEFS excluded prekindergarten programs. In these three states, the NPEFS total student membership variable excludes prekindergarten membership. Illinois and Wisconsin did not report finance data for charter schools in the FY 10 NPEFS survey. NCES edited student membership for Illinois and Wisconsin by excluding students from districts where all associated schools are charter schools.

Totals. National totals reported in the tables are limited to the 50 states and the District of Columbia and do not include data from Puerto Rico or the four other jurisdictions of American Samoa, Guam, the Commonwealth of the Northern Mariana Islands, or the U.S. Virgin Islands.

Current expenditures. Researchers generally use current expenditures instead of total expenditures when comparing education spending between states or across time because current expenditures exclude expenditures for capital outlay, which tend to have dramatic increases and decreases from year to year. Also, the current expenditures commonly reported are for public elementary and secondary education only. Many school districts also support community services, adult education, private education, and other programs, which are included in total expenditures. These programs and the extent to which they are funded by school districts vary greatly both across and within states.

Comparability of fiscal data across states. Because the District of Columbia is a single urban district, it is often an outlier in comparisons of revenues and expenditures, with larger revenues and expenditures per student than most states have. Similarly, Hawaii is a single school district and funds public education primarily through state taxes. Because of this, Hawaii’s data may be distinctive compared to other states.

Inflation-adjusted data. Data in tables 4 and 5 and figure 2 in this report have been adjusted to FY 10 dollars to account for inflation using the Consumer Price Index (CPI) adjusted to a fiscal year basis (July through June). The CPI is published by the U.S. Labor Department, Bureau of Labor Statistics. This price index measures the average change in inflation of a fixed market basket of goods and services purchased by consumers.

Fiscal years. The fiscal year begins on July 1 and ends on June 30 for most states. The fiscal year for Alabama runs from October 1 through September 30, and the fiscal year for Nebraska and Texas runs from September 1 through August 31. NCES does not adjust NPEFS data to conform to a uniform fiscal year across states.

3 The first Pilot Teacher Compensation Survey was launched by the National Center for Education Statistics (NCES) in 2007, collecting school year 200506 data.