SABS Frequently Asked Questions

The primary purpose of the SABS survey was to create a foundational data collection to help researchers and the public explore the role of location in education. Unlike school district boundaries and school point locations, NCES lacked a basic set of school attendance area boundaries that could be used to help investigate spatial variation within school districts. In addition to providing basic data infrastructure, the SABS boundaries serve three other important purposes. First, they can be integrated with other sources of school data in a geographic information system (GIS) to help visualize spatial conditions or patterns in data that may not be detectable in traditional tables or graphs. Second, students typically attend multiple schools during the course of their elementary and secondary education, and this progression may have important effects on student outcomes. Although SABS did not systematically collect information about school feeder relationships, the spatial relationships between elementary, middle, and high school attendance areas may offer useful approximations until more definitive data can be collected by other sources. Lastly, school boundaries can be used with a GIS to create new data indicators to support additional analysis.

The SABS boundaries were originally designed and developed by local school officials to meet local needs. They were provided to NCES through the generous cooperation of school district and state officials throughout the U.S. Boundaries were submitted in paper and digital formats, and districts also had the option of digitizing boundaries directly through an online mapping tool developed to support the survey collection. In some cases state-wide collections had already been assembled and were provided to NCES by state education officials.

Large-scale collection of attendance area boundaries was initiated by Dr. Salvatore Saporito and a team from The College of William & Mary in the early 2000s as part of an effort to examine school-level demographic conditions. This effort integrated population data from the 2000 decennial census with administrative data from the 1999-2000 NCES Common Core of Data (CCD) to allow for demographic and economic analysis of individual school areas for the largest 100 districts in the U.S. This effort was expanded in 2008 to create the School Attendance Boundary Information System (SABINS), a data infrastructure project supported by the National Science Foundation. SABINS included grade-specific attendance boundaries from over 500 districts for the 2009-2010 academic year. More information about the SABINS project can be found at SABINS Public School Data. In 2011 NCES coordinated with SABINS to support a collection of the 600 largest districts in the U.S. The boundaries were assembled and associated with school-level attributes from the CCD and made available for download from the SABS website.

NCES launched the first SABS survey in 2013 to collect boundaries for the 2013-2014 school year and initiated the follow-up 2015-2016 collection in the fall of 2015. Survey operations closed at the end of the 2015-2016 collection cycle.

The school level indicator (elementary, middle, high, and other) relied on the school level assignment provided by the NCES Common Core of Data (CCD) program. The CCD defines four school levels:

• Elementary (Low Grade: PK through 03; High Grade: PK through 08)
• Middle (Low Grade: 04 through 07; High Grade: 04 through 09)
• High (Low Grade: 07 through 12; High Grade: 12 only)
• Other (any other configuration not falling within the above three categories, including ungraded and operational schools)

School districts were considered for the SABS universe if they were included in the Census Bureau’s 2015-16 School District Review Program (SDRP) and identified as a regular Local Education Agency (LEA) or component of a supervisory union in the 2014-15 NCES Common Core of Data (CCD) (i.e., District Type = 1 or 2) that operated at least one qualifying school. Schools in the qualifying districts were included in the survey if they were identified in the 2015-2016 CCD as a currently open regular school (Type =1) that was not a charter, magnet, adult education, or virtual school, and operated at least one grade greater than prekindergarten with enrolled students. In some instances, magnet, charter, and other non-regular schools were included in the survey because the student population was drawn from a typical address-based attendance boundary. Otherwise, magnet, charter, virtual, special education, vocational education, pre-kindergarten schools, and alternative schools were excluded by default because these schools commonly accept students based on factors other than home address. Additionally, some schools defined by CCD as a regular school did not maintain attendance boundaries and instead allowed open enrollment from throughout the district. These cases are flagged as Open Enrollment on the SABS data file.

The SABS collection is available at https://nces.ed.gov/programs/edge/sabs. EDGE data can also be explored and added as a web services at data-nces.opendata.arcgis.com.

The SABS shapefiles are in the WGS_1984_Web_Mercator_Auxiliary_Sphere coordinate system.

The SABS boundaries and associated school attributes are provided as a shapefile, which is a standard format for housing geographic data. Due to the large size of the SABS shapefiles, the data are compressed and provided for download as a .ZIP file. School attribute data are available as a .CSV table within the ZIP. EDGE data can also be explored and added as a web services at data-nces.opendata.arcgis.com.

Schools rarely operate more than one attendance boundary to provide different catchment areas for different grades within the same school. This condition affected 0.6% of the schools in the 2010-2011 update file that was used to plan the SABS collection. In the rare cases where this occurs, the boundaries were combined and the final school boundary reflects the maximum extent of the combined areas.

SABS collected boundaries for regular schools that rely on geographically-defined attendance areas. Many magnet and charter schools operate open enrollment policies that accept students from areas not determined by their home address, therefore magnet schools, charter schools, and virtual schools were not included in the SABS collection.

Some districts may appear to have a gap in coverage due to the CCD's school level definitions. For example, the Middle school layer may appear to have missing boundaries in areas that are only served by K-8 schools because K-8 schools are classified as Primary schools.

School district boundaries are updated every other year for NCES by the U.S. Census Bureau. District boundaries may change between update cycles, and therefore boundaries based on the 2015-2016 SABS collection may not match the extent of current district boundaries. For more information about the School District Review Program, see https://www.census.gov/geo/partnerships/sdrp.html.

Most districts in Vermont were out of scope due to their district type classification. One of the basic requirements for inclusion in SABS was that schools had to be in districts that were geographically defined and had boundaries included in Census TIGER. The 2015-2016 Census district boundary update for Vermont primarily reflected boundaries for supervisory union districts. However, since CCD still associated the school IDs with their regular districts (not the supervisory unions), this resulted in geographically-defined districts that lacked associations with qualifying schools. Because the boundaries for the regular districts were not included in TIGER, the schools in those districts could not be represented in SABS.