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Note 1: Commonly Used Variables (2010)

Certain common variables, such as parents' education, race/ethnicity, community type, and poverty, are used in the various surveys cited in The Condition of Education 2010. The definitions for these variables can vary across surveys and sometimes between different time periods of a single survey. This supplemental note describes how several common variables used in various indicators in this volume are defined in each of the surveys. In addition, this note describes how certain terms are used in these indicators.

Parents' Education

Parents' level of education is generally measured by either the highest level of education attained by the mother or the highest level of education attained by either parent. Indicator 14 reports parents' highest level of education based on a question in the National Assessment of Educational Progress (NAEP) that asks students in grades 8 and 12 to indicate the highest level of education completed by each parent. Students could choose from "did not finish high school," "graduated from high school," "some education after high school," "graduated from college," and "I don't know." For more information on NAEP, see supplemental note 4.

In indicator 20, which is based on data from the Current Population Survey (CPS), parents' level of education is the highest level of education attained by either the highest educational attainment of the two parents who reside with the student or, if only one parent is in the residence, the highest educational attainment of that parent. When neither parent resides with the student, it is defined as the highest educational attainment of the householder. For more information on the CPS, see supplemental note 2.


The categories denoting race and ethnicity in The Condition of Education are in accordance with the 1997 Office of Management and Budget (OMB) standard classification scheme. These classifications are designed to provide comparable data to monitor equal access in areas such as housing, education, and employment for population groups that historically have experienced discrimination and differential treatment because of their race or ethnicity. By using the OMB standards to tabulate data in these areas by race and ethnicity, it is possible to compare disparities across data systems. While the federal categories provide a standardized format for purposes of collecting and presenting data on race and ethnicity, the standard was not designed to capture the full complexity of race and ethnicity in the United States.

The 1997 standards emphasize self-reporting or self-identification as the preferred method for collecting data on race and ethnicity. The standards do not establish criteria or qualifications (such as blood quantum levels) that are to be used in determining a particular individual's racial or ethnic classification. They do not specify how an individual should classify himself or herself. In situations where self-reporting is not practicable or feasible, observer identification may be used. For indicator 3, which uses data from the Private School Survey, racial/ethnic classifications are based on school reports of race/ethnicity for aggregate K–12 enrollment. The 1997 standards reflect a change in data collection policy, making it possible for federal agencies to collect information that reflects the increasing diversity of the United States population.

Under the OMB standards, "Hispanic or Latino" is an ethnicity category, not a racial category. Agencies that collect data on race and ethnicity separately must collect data on ethnicity first. Ethnicity is categorized as follows:

  • Hispanic or Latino: A person of Cuban, Mexican, Puerto Rican, South or Central American, or other Spanish culture or origin, regardless of race.

Race categories presented in The Condition of Education 2010 exclude persons of Hispanic ethnicity; thus, the race/ethnicity categories are mutually exclusive.

Racial groupings are as follows:

  • American Indian or Alaska Native: A person having origins in any of the original peoples of North and South America (including Central America) who maintains tribal affiliation or community attachment.
  • Asian: A person having origins in any of the original peoples of the Far East, Southeast Asia, and the Indian subcontinent: for example, Cambodia, China, India, Japan, Korea, Malaysia, Pakistan, the Philippines, Thailand, and Vietnam.
  • Black: A person having origins in any of the Black racial groups of Africa.
  • Native Hawaiian or Other Pacific Islander: A person having origins in any of the original peoples of Hawaii, Guam, Samoa, or other Pacific Islands.
  • White: A person having origins in any of the original peoples of Europe, North Africa, or the Middle East.
  • Two or more races: A person who selected two or more of the following racial categories when offered the option of selecting one or more racial designations: White, Black, Asian, Native Hawaiian or Other Pacific Islander, or American Indian or Alaska Native.

In The Condition of Education, the following terms are typically used to represent the above categories: White, Black, Hispanic, Asian, Pacific Islander, American Indian/Alaska Native, and Two or more races. Not all categories are shown in all indicators. In some cases, categories are omitted because there are insufficient data in some of the smaller categories or because the data collection design did not distinguish between groups (between Asians and Pacific Islanders, for example). For example, in the Common Core of Data (CCD), the categories Asian and Pacific Islander are combined and "Two or more races" is not an option for respondents.

In other cases, omissions occur because only comparable data categories are shown. For example, the category "Two or more races," which was introduced in the 2000 Census and became a regular category for data collection in the Current Population Survey (CPS) in 2003, is sometimes excluded from indicators that present a historical series of data with constant categories, and it is sometimes included within the category "Other." For further details on these classifications, see the source documentation of the particular survey and

In The Condition of Education 2010, the above definitions of race/ethnicity apply to indicators 3, 4, 5, 6, 9, 10, 11, 12, 13, 14, 17, 19, 20, 22, 23, 24, 25, 26, 27, 28, 29, and 39. These definitions may or may not apply to indicators 8, 21, 23, and 32, which use data from the Integrated Postsecondary Education Data System (IPEDS). The above definitions are currently being phased into the IPEDS data collection for academic year 2008–09. For more information on IPEDS, see supplemental note 3.

Community Type

Federal departments and agencies use various classification systems to define community types. Indicators in The Condition of Education rely on one or a combination of the following three classification systems: the Office of Management and Budget's system of metropolitan areas, which is used by the Census Bureau; the Census Bureau's system of urbanized/urban/rural areas; and the National Center for Education Statistics (NCES) system of locale codes, although most indicators in The Condition of Education 2010 use the revised urban-centric locale code system that NCES released in 2006.

Metropolitan Areas
The Census Bureau's Current Population Survey (CPS) classifies community type based on the concept of a metropolitan area, which has changed in its application over time. Between 1990 and 2000, the Census and the CPS used the term "metropolitan area" (MA) to collectively refer to Metropolitan Statistical Areas (MSAs), Primary Metropolitan Statistical Areas (PMSAs), and Consolidated Metropolitan Statistical Areas (CMSAs) (defined below). In 2000, the Census adopted the term "Core Based Statistical Area" (CBSA), which collectively refers to metropolitan statistical areas and (the newly introduced concept of) micropolitan statistical areas.

Metropolitan Areas—1990 Standards
The Office of Management and Budget defines and designates metropolitan areas, following standards established by the interagency Federal Executive Committee on Metropolitan Areas, with the aim of producing definitions that are as consistent as possible for all MAs nationwide. Under its 1990 standards, the OMB defined an MA as "a large population nucleus, together with adjacent communities that have a high degree of economic and social integration with that core." The Census Bureau used this definition for an MA from 1990 to 2000. (See for more details.)

In order to be designated as an MA under the 1990 standards, an area had to meet one or both of the following criteria: (1) include a city with a population of at least 50,000 or (2) include a Census Bureau-defined urbanized area of at least 50,000 and have a total MA population of at least 100,000 (75,000 in New England). Under the 1990 standards, the "central county" (or counties) contained either the central city (defined below) or at least 50 percent of the population of the central city, or had at least 50 percent of its population in an urbanized area. Additional "outlying counties" were included in the MA if they met specified requirements of commuting to the central counties and selected requirements of metropolitan character (such as population density and percent urban). In New England, MAs were defined in terms of cities and towns, following rules analogous to those used with counties elsewhere.

The individual counties (or other geographic entities) comprising each MA were either designated as a Metropolitan Statistical Area (MSA) or, if the MA was large enough (1 million in population or more), as a Consolidated Metropolitan Statistical Area (CMSA) composed of two or more Primary Metropolitan Statistical Areas (PMSAs). For example, the PMSA "Milwaukee-Waukesha, WI" was combined with the PMSA "Racine, WI" to form the CMSA of "Milwaukee-Racine, WI." CMSAs could span states, as was the case with the CMSA "Philadelphia-Wilmington-Atlantic City, PA-NJ-DE-MD." (In June 1999, there were 258 MSAs and 18 CMSAs in the United States, which included a total of 73 PMSAs.)

All territory, population, and housing units inside of MAs were characterized as metropolitan. Any territory, population, or housing units located outside of an MA were defined as nonmetropolitan. The largest city in each MA was designated a central city, and additional cities could qualify as such if specified requirements were met concerning population size and commuting patterns. (In June 1999, there were 542 central cities in the United States plus 12 in Puerto Rico.)

Together these classifications were used to define a location's MA Status as one of the following:

  • Central city,
  • Balance of an MA (meaning any territory that is metropolitan but not in a central city), or
  • Nonmetropolitan.

Metropolitan and Micropolitan Statistical Areas—2000 Standards
In 2000, the OMB defined a metropolitan or micropolitan statistical areas as "a core area containing a substantial population nucleus, together with adjacent communities having a high degree of economic and social integration with that core." Together, metropolitan and micropolitan statistical areas are considered to constitute the "Core Based Statistical Area" (CBSA). Currently defined metropolitan and micropolitan statistical areas are based on the application of OMB's 2000 standards to 2000 decennial census data. (Current metropolitan and micropolitan statistical area definitions were announced by OMB effective June 6, 2003.)

In order to be designated as a CBSA under the 2000 standards, an area must contain at least one "urban" area (that is, an urbanized area or urban cluster—see definitions of urbanized area and urban cluster below) with a population of 10,000 or more. Each metropolitan statistical area—now referred to as a "metro area" to distinguish it from the metropolitan statistical areas referred to as "MSAs" under the 1990 standards—must have at least one urbanized area of 50,000 or more inhabitants. Each micropolitan statistical area must have at least one urban cluster with a population of at least 10,000 but less than 50,000. Under the standards, the county (or counties) in which at least 50 percent of the population resides in urban areas with populations of 10,000 or more, or that contains at least 5,000 people residing in a single urban area with a population of 10,000 or more, is identified as a "central county" (or counties). Additional "outlying counties" are included in the CBSA if they meet specified requirements of commuting to or from the central counties. Counties or equivalent entities form the geographic "building blocks" for metropolitan and micropolitan statistical areas throughout the United States and Puerto Rico. (As of June 6, 2000, there were 362 metropolitan statistical areas and 560 micropolitan statistical areas in the United States. In addition, there were eight metro areas and five micropolitan statistical areas in Puerto Rico. See estimates/aboutmetro.html for more details.)

Exhibit B-1. Metropolitan areas—1990 and 2000 standards

Together, these classifications are used to define a location's CBSA status (or, if no micropolitan statistical areas are included, metro area status) as one of the following:

  • Principal city of a CBSA (or metro area),
  • Located in a CBSA (or metro area), but not in the principal city, or
  • Not located in a CBSA (or metro area).

As with the previous MA status classifications under the 1990 standards, the CBSA status classifications under the 2000 standards do not equate to an urban-rural classification; all counties included in metropolitan and micropolitan statistical areas (and many other counties) contain both urban and rural areas.

Urbanized, Urban, and Rural Areas
The Census Bureau divides the entire geographic area of the United States, Puerto Rico, and the Island Areas according to a concept of urban and rural areas. As with metropolitan statistical areas, the Census Bureau revised the urban/rural concept and criteria for the 2000 Census. The criteria that had been in place between 1990 and 2000, however, were used to create the NCES codes (described below). Thus, this supplemental note explains the 1990–2000 criteria in detail so that readers can fully understand the definitions.

From the adoption of the urban/rural concept for the 1950 Census until the 2000 Census, an urbanized area consisted of one or more "central places" and the adjacent densely settled surrounding "urban fringe" that together had a minimum population of 50,000. A "place" was either an incorporated governmental unit, such as a city, village, borough, or town, or a Census Designated Place (CDP), which was an unincorporated population cluster for which the Census Bureau delineates boundaries in cooperation with state and local agencies. All of the territory within the urbanized area that was outside the central place or places comprised the "urban fringe." Territory included in the urban fringe generally had a population density of at least 1,000 people per square mile, but could include lower density territory that contained nonresidential urban land uses (e.g., areas zoned for commercial or industrial use or reserved for recreational purposes) or served to link outlying densely settled territory with the main body of the urbanized area. The Census Bureau defined as urban any incorporated places (cities, towns, villages, etc.) or CDPs outside urbanized areas that contained a population of 2,500 or more.

The Census Bureau also expanded the definition of places to include extended cities. Extended cities were incorporated places whose boundaries encompassed substantial amounts of low-density territory (less than 100 people per square mile) relative to the overall land area of the place. The Census Bureau then identified both urban and rural territory in such places, thus providing exceptions to the general rule that places were classified as entirely urban or entirely rural. There were 182 extended cities in 1990. The decision to ignore place boundaries when defining urban areas for the 2000 Census (see below) made the extended city concept obsolete; under the 2000 criteria, any place potentially can be divided into urban and rural components. No survey employed in this volume of The Condition of Education includes extended cities in its community type definition.

The Census Bureau then classified all territory, population, and housing units not classified as urbanized or urban as rural. For further details, see

Beginning with the 2000 Census, the Census Bureau has employed new definitions of urban areas based on the concepts of urbanized areas and urban clusters, the former being similar to the urbanized area under the 1990 definitions and the latter replacing the concept of urban fringe and urban areas. Urbanized areas and urban clusters consist of densely settled census block groups and census blocks that meet specified minimum population density requirements. Urbanized areas continue to have minimum populations of 50,000; urban clusters have populations of at least 2,500 and less than 50,000. Place boundaries are no longer taken into consideration when defining these two types of urban areas. (Under the previous classification system, place boundaries were used to determine the urban/rural classifications of territory: all incorporated places that had at least 2,500 people were classified as urban if they were outside an urbanized area.) Thus, the Census Bureau's current urban area classification provides a seamless, nationally consistent method of defining urban areas that is not affected by varying state laws governing incorporation and annexation. For further details on the revised definitions, see (For differences between the 1990 Census and 2000 Census Urbanized Area Criteria, see

Locale Code
In the NCES Common Core of Data (CCD), the community type of schools is classified according to an urban-centric "Locale Code" system. Locale codes are assigned to each school according to the school's physical location (longitude and latitude). There are four major categories within the urban-centric locale code classification system: (1) city, (2) suburban, (3) town, and (4) rural. Each major category is divided into three subcategories. Cities and suburban areas are subdivided into the categories of small, midsize, and large; towns and rural areas are subdivided by their proximity to an urbanized area into the categories of fringe, distant, and remote (see exhibit B-2). These 12 categories are based on three key concepts that the Census Bureau uses to define an area's urbanicity: principal city, urbanized area, and urban cluster. A principal city is a city that contains the primary population and economic center of a metropolitan statistical area, which, in turn, is defined as one or more contiguous counties that have a "core" area with a large population nucleus and adjacent communities that are highly integrated economically or socially with the core. Urbanized areas and urban clusters are densely settled "cores" of Census-defined blocks with adjacent densely settled surrounding areas. Core areas with populations of 50,000 or more are designated as urbanized areas; those with populations between 25,000 and 50,000 are designated as urban clusters. For more information on urbanized areas and urban clusters, see Rural areas are designated by Census as those areas that do not lie inside an urbanized area or urban cluster.

NCES has classified all schools into one of these 12 categories based on schools' actual addresses and their corresponding coordinates of latitude and longitude. Not only does this mean that the location of any school can be identified precisely, but also that distance measures can be used to identify town and rural subtypes. Unlike the previous classification system that differentiated towns on the basis of population size, the new system differentiates towns and rural areas on the basis of their proximity to larger urban centers.

School districts' locale codes are assigned through the use of these urban-centric locale codes, according to classification rules such as the following: if 50 percent or more of students in the district attend schools that are located in a single locale code, that code is assigned to the district. If no single locale code accounts for 50 percent of the students, then the major category (city, suburban, town, or rural) with the greatest percentage of students determines the locale. Districts with no schools or students are given a locale code of "N." For more information on the urban-centric locale code system, see

Besides being used for the CCD, the expanded 12-level locale codes are used to categorize community type in other NCES surveys. Typically, however, the locale codes are reported as the four major categories of city, suburban, town, and rural.

In The Condition of Education 2010, urban-centric locale codes are used in indicators 3, 14, 24, 25, 26, 31, 32, 36, and 37.

Exhibit B-2. NCES urban-centric locale categories


Data on household income and the number of people living in the household are combined with estimates of the poverty threshold, published by the Census Bureau, to determine the poverty status of children (or adults). The thresholds used to determine poverty status for an individual differ for each survey year. The weighted average poverty thresholds for various household sizes for 1990, 1995, and 2000 through 2007 are shown in exhibit B-3. (For thresholds for other years, see

In indicator 5, children in families whose incomes are below the poverty threshold are classified as poor, those in families with incomes at 100–199 percent of the poverty threshold are classified as near-poor, and those in families with incomes at 200 percent or more of the poverty threshold are classified as nonpoor.

In indicator 5, poverty status is based on Census Bureau guidelines for the year that corresponds with the year of the estimate. Poverty status for the 9-month estimates reflects poverty status at the time of the 9-month data collection, poverty status for the 2-year estimates reflects poverty status at the time of the 2-year collection, and poverty status for the preschool estimates reflects poverty status at the time of the preschool year collection. Census Bureau guidelines identify a dollar amount that would allow a household to meet its needs, given its size and composition. For example, in 2002, a family of four was considered to live below the poverty threshold if its income was less than or equal to $18,392. Children in families whose incomes were below the poverty threshold were classified as being in poverty; those in families with incomes at 100 percent or more of the poverty threshold were classified as being at or above poverty.

Eligibility or approval for the National School Lunch Program also serves as a measure of poverty status. The National School Lunch Program is a federally-assisted meal program operated in public and private nonprofit schools and residential child care centers. Unlike the poverty thresholds discussed above, which rely on dollar amounts determined by the Census Bureau, eligibility for the National School Lunch Program relies on the federal income poverty guidelines of the Department of Health and Human Services. To be eligible for free lunch, a student must be from a household with an income at or below 130 percent of the federal poverty guideline; to be eligible for reduced-price lunch, a student must be from a household with an income at or below 185 percent of the federal poverty guideline. Title I basic program funding relies on free lunch eligibility numbers as one (of four) possible poverty measures for levels of Title I federal funding.

In The Condition of Education 2010, eligibility for the National School Lunch Program applies to indicators 9, 10, 11, 12, 14, 24, 25, 26, 30, 31, 36, and 37; approval for the National School Lunch Program applies to indicator 24. indicator 30 also discusses approval for the National School Lunch Program.

Small Area Income and Poverty Estimates (SAIPE) Program
The goal of the Census Bureau's Small Area Income and Poverty Estimates (SAIPE) program is to make intercensal estimates of median income and numbers in poverty for states, counties, and school districts. indicator 36 employs SAIPE's school district estimates of the population of children ages 5–17 and the number of related children ages 5–17 in families in poverty. This indicator employs the SAIPE data, rather than the free lunch-eligibility data, to measure poverty by school district because SAIPE data are available for all regular operating school districts, while free lunch-eligibility data are missing for a sizable number of school districts. Further, the SAIPE poverty data are constructed using consistent methodology, while the designation of free lunch eligibility may differ from school to school. More information on SAIPE is available at

Exhibit B-3. Weighted average poverty thresholds, by household size: Selected years, 1990–2008

Geographic Region

The regional classification systems in exhibit B-4 represent the four geographical regions of the United States as defined by the Census Bureau of the U.S. Department of Commerce. In The Condition of Education 2010, indicators 2, 3, 5, 19, 24, 25, and 32 use this system.

Exhibit B-4. U.S. Census Bureau, Regional Classification

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