The National Center for Education Statistics bases a particular district’s locale code on the locale codes assigned to individual schools within each district. To determine a district locale code, NCES applies two rules:
- If 50 percent or more of the district’s students attend schools with the same locale code, the district is assigned that particular code;
- If there is not a majority of students attending schools in one locale code, the district’s locale code is determined by plurality — that is, the district is assigned whichever school-based locale code contains the largest number of students.[*]
The “urban-centric” locale code categorizes urban and suburban areas into subgroups based on their size, and categorizes town and rural areas based on their distance from urbanized areas and urban clusters. Distances are determined using straight-line or “Euclidean” distance. Although this methodology “does not account for the presence or absence of road networks that may offer point-to-point drive time estimates,” NCES justifies it by pointing out that it is not affected by transportation infrastructure modifications that could produce “significant fluctuations,” and it “provides data users with a simple and familiar concept that is analytically useful and relatively easy to implement.”[†]
The verbatim definitions of the 12 different locale codes appear in Graphic 29.
Graphic 29: NCES Locale Code Definitions (Verbatim From Original)[‡]
Source: National Center for Education Statistics
NCES uses the following definitions to clarify the terms contained in Graphic 29 (verbatim from original):[§]
Principal City. Principal cities include the largest place (incorporated or unincorporated) and other relatively large places that serve as the primary population and employment centers within a CBSA. Principal cities replaced the older central city term defined by OMB’s 1990 metropolitan area standards, recognizing that many central cities have become much less central (functionally and structurally) within increasingly polynucleated urban areas. Although principal cities are present in both metropolitan and micropolitan statistical areas, CCD City locale classifications are currently limited to principal cities of metropolitan statistical areas only.
Rural. The Census Bureau classifies all population and territory not included in an urbanized area or urban cluster as rural.
Urban (urbanized areas and urban clusters). The Census Bureau defines an urban area as a densely settled core of census block groups and census blocks that meet minimum population density requirements, along with adjacent densely settled surrounding census 10 blocks. When a core area contains a population of 50,000 or more, it is classified as an urbanized area (UA). Core areas with population between 2,500 and 50,000 are classified as urban clusters (UC).
[*] Phan and Glander, “Documentation to the NCES Common Core of Data Local Education Agency Locale Code File: School Year 2005-06 “(National Center for Education Statistics, 2007), 5, http://nces.ed.gov/ccd/ pdf/al051agen.pdf (accessed Feb. 22, 2011).
[†] Ibid., 7-8.
[‡] Ibid., 3-4.
[§] Ibid., 9-10.