Documentation: Census 2010
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Publisher: U.S. Census Bureau
Survey: Census 2010
Document: Summary File 1 Technical Documentation
citation:
Social Explorer, U.S. Census Bureau; 2010 Census of Population and Housing, Summary File 1: Technical Documentation, Issued June 2011.
Chapter Contents
Summary File 1 Technical Documentation
Appendix B. Definitions of Subject Characteristics
Introduction
The 2010 Census data products provide, except where specifically noted, counts of the resident population of the United States. The U.S. resident population includes everyone whose usual place of residence was in the 50 states and the District of Columbia at the time of the 2010 Census.
In the design of summary file tables, the Census Bureau strives for consistency in terminology and cell label structure to facilitate processing, review, and usability. Data users see the same patterns repeated in various cross-tabulated tables. Unfortunately, at times, the use of a pattern creates illogical results, such as the display of data for the population 65 years and over in juvenile correctional facilities.
Population Characteristics
The data on age were derived from answers to a two-part question (i.e., age and date of birth). The age classification for a person in census tabulations is the age of the person in completed years as of April 1, 2010, the census reference date. Both age and date of birth responses are used in combination to
determine the most accurate age for the person as of the census reference date. Inconsistently reported and missing values are assigned or allocated based on the values of other variables for that person, from other people in the household or from people in other households (i.e., hot-deck imputation).
Age data are tabulated in age groupings and single years of age. Data on age also are used to classify other characteristics in census tabulations.


Median Age
This measure divides the age distribution into two equal parts: one-half of the cases falling below the median value and one-half above the value. Median age is computed on the basis of a single-year-of-age distribution using a linear interpolation method.

Limitation of the data
There is some tendency for respondents to provide their age as of the date they completed the census questionnaire or interview, not their age as of the census reference date. The two-part question and editing procedures have attempted to minimize the effect of this reporting problem on tabulations. Additionally, the current census age question displays the census reference date prominently, and interviewer training emphasizes the importance of collecting age as of the reference date.

Respondents sometimes round a persons age up if they were close to having a birthday. For most single years of age, the misstatements are largely offsetting. The problem is most pronounced at age 0. Also, there may have been more rounding up to age 1 to avoid reporting age as 0 years. (Age in completed months was not collected for infants under age 1.) Editing procedures correct this problem.

There is some respondent resistance to reporting the ages of babies in completed years (i.e., 0 years old when the baby is under 1 year old). Instead, babies ages are sometimes reported in months. The two-part question along with enhanced editing and data capture procedures correct much of this problem before the age data are finalized in tabulations. Additionally, the current census age question includes an instruction for babies ages to be answered as 0 years old when they are under 1 year old.

Age heaping is a common age misreporting error. Age heaping is the tendency for people to overreport ages (or years of birth) that end in certain digits (commonly digits 0 or 5) and underreport ages or years of birth ending in other digits. The two-part question helps minimize the effect of age heaping on the final tabulations.

Age data for centenarians have a history of data quality challenges. The counts in the 1970 and 1980 Censuses for people 100 years and over were substantially overstated. Editing and data collection methods have been enhanced in order to meet the data quality challenges for this population.

It also has been documented that the population aged 69 in the 1970 Census and the population aged 79 in the 1980 Census were overstated. The population aged 89 in 1990 and the population aged 99 in 2000 did not have an overstated count. (For more information on the design of the age question, see the Comparability section below.)

Comparability
Age data have been collected in every census. However, there have been some differences in the way they have been collected and processed over time. In the 2010 Census (as in Census 2000), each individual provided both an age and an exact date of birth. The 1990 Census collected age and year of birth. Prior censuses had collected month and quarter of birth in addition to age and year of birth. The 1990 Census change was made so that coded information could be obtained for both age and year of birth.

In each census since 1940, the age of a person was assigned when it was not reported. In censuses before 1940, with the exception of 1880, people of unknown age were shown as a separate category. Since 1960, assignment of unknown age has been performed by a general procedure described as imputation. The specific procedures for imputing age have been different in each census. (For more information on imputation, see 2010 Census: Operational Overview and Accuracy of the Data.)

Alaska Native Tribe
See "Race."
American Indian Tribe
See "Race."
Foster Children
See "Other Nonrelatives in Household Type and Relationship."

Hispanic or Latino Origin
The data on the Hispanic or Latino population were derived from answers to a question that was asked of all people. The terms Hispanic,Latino, and Spanish are used interchangeably. Some respondents identify with all three terms, while others may identify with only one of these three specific terms. People who identify with the terms Hispanic,Latino, or Spanish are those who classify themselves in one of the specific Hispanic, Latino, or Spanish categories listed on the questionnaire (Mexican,Puerto Rican, or Cuban) as well as those who indicate that they are another Hispanic, Latino, or Spanish origin. People who do not identify with one of the specific origins listed on the questionnaire but indicate that they are another Hispanic, Latino, or Spanish origin are those whose origins are from Spain, the Spanish-speaking countries of Central or South America, or the Dominican Republic. Up to two write-in responses to the another Hispanic, Latino, or Spanish origin category are coded.

Origin can be viewed as the heritage, nationality group, lineage, or country of birth of the person or the persons parents or ancestors before their arrival in the United States. People who identify their origin as Hispanic, Latino, or Spanish may be any race.

Some tabulations are shown by the origin of the householder. In all cases where the origin of households, families, or occupied housing units is classified as Hispanic, Latino, or Spanish, the origin of the householder is used. (See the discussion of householder under "Household Type and Relationship.")

If an individual did not provide a Hispanic origin response, his or her origin was allocated using specific rules of precedence of household relationship. For example, if origin was missing for a natural-born child in the household, then either the origin of the householder, another natural-born child, or spouse of the householder was allocated.
If Hispanic origin was not reported for anyone in the household and origin could not be obtained from a response to the race question, then their origin was assigned based on their prior census record (either from Census 2000 or the American Community Survey), if available. If not, then the Hispanic origin of a householder in a previously processed household with the same race was allocated. (For more information on allocation, see "2010 Census: Operational Overview and Accuracy of the Data.") As in Census 2000, surnames (Spanish and non-Spanish) were used to assist in allocating an origin or race.

Comparability
There are four changes to the Hispanic origin question for the 2010 Census. First, the wording of the question differs from that in 2000. In 2000, the question asked if the person was Spanish/Hispanic/Latino. In 2010, the question asks if the person is of Hispanic, Latino, or Spanish origin. Second, in 2000, the question provided an instruction, Mark ý the 'No'box if not Spanish/Hispanic/Latino. The 2010 Census question provided no specific instruction for non-Hispanics. Third, in 2010, the Yes, another Hispanic, Latino, or Spanish origin category provided examples of six Hispanic origin groups (Argentinean, Colombian, Dominican, Nicaraguan, Salvadoran, Spaniard, and so on) and instructed respondents to print origin. In 2000, no Hispanic origin examples were given. Finally, the fourth change was the addition of a new instruction in the 2010 Census that was not used in Census 2000. The instruction is stated as follows: NOTE: Please answer BOTH Question 8 about Hispanic origin and Question 9 about race. For this census, Hispanic origins are not races.

There were two changes to the Hispanic origin question for Census 2000. First, the sequence of the race and Hispanic origin questions for Census 2000 differs from that in 1990; in 1990, the race question preceded the Hispanic origin question. Testing prior to Census 2000 indicated that response to the Hispanic origin question could be improved by placing it before the race question without affecting the response to the race question. Second, there was an instruction preceding the Hispanic origin question indicating that respondents should answer both the Hispanic origin and the race questions. This instruction was added to give emphasis to the distinct concepts of the Hispanic origin and race questions, and emphasized the need for both pieces of information.

Furthermore, there was a change in the processing of the Hispanic origin and race responses. In the 1990 census, respondents provided Hispanic origin responses in the race question and race responses in the Hispanic origin question. In 1990, the Hispanic origin question and the race question had separate edits; therefore, although information may have been present on the questionnaire, it was not fully utilized due to the discrete nature of the edits. However, for Census 2000, there was a joint race and Hispanic origin edit that utilized Hispanic origin and race information regardless of the location.

Household Type and Relationship
Household
A household includes all the people who occupy a housing unit. (People not living in households are classified as living in group quarters.) A housing unit is a house, an apartment, a mobile home, a group of rooms, or a single room that is occupied (or if vacant, is intended for occupancy) as separate living quarters. Separate living quarters are those in which the occupants live separately from any other people in the building and which have direct access from the outside of the building or through a common hall. The occupants may be a single family, one person living alone, two or more families living together, or any other group of related or unrelated people who share living arrangements. In the 2010 Census data products, the count of households or householders equals the count of occupied housing units.

Average Household Size
Average household size is a measure obtained by dividing the number of people in households by the number of households. In cases where people in households are cross-classified by race or Hispanic origin, people in the household are classified by the race or Hispanic origin of the householder rather than the race or Hispanic origin of each individual. Average household size is rounded to the nearest hundredth.

Relationship to Householder
Householder
The data on relationship to householder were derived from answers to Question 2, which was asked of all people in housing units. One person in each household is designated as the householder. In most cases, this is the person, or one of the people, in whose name the home is owned, being bought, or rented and who is listed on line one of the questionnaire. If there is no such person in the household, any adult household member 15 years old and over could be designated as the householder.
Households are classified by type according to the sex of the householder and the presence of relatives. Two types of householders are distinguished: a family householder and a nonfamily householder. A family householder is a householder living with one or more individuals related to him or her by birth, marriage, or adoption. The householder and all people in the household related to him or her are family members. A nonfamily householder is a householder living alone or with nonrelatives only.

Spouse
The spouse category includes a person identified as the husband or wife of the householder and who is of the opposite sex. For most of the tables, unless otherwise specified, it does not include same-sex spouses even if a marriage was performed in a state issuing marriage certificates for same-sex couples.

The child category includes a son or daughter by birth, a stepchild, or adopted child of the householder, regardless of the childs age or marital status. The category excludes sons-in-law, daughters-in-law, and foster children.

Biological Son or Daughter
The son or daughter of the householder by birth.
Adopted Son or Daughter
The son or daughter of the householder by legal adoption. If a stepson, stepdaughter, or foster child has been legally adopted by the householder, the child is then classified as an adopted child.
Stepson or Stepdaughter
The son or daughter of the householder through marriage but not by birth, excluding sons-in-law and daughters-in-law. If a stepson or stepdaughter of the householder has been legally adopted by the householder, the child is then classified as an adopted child.

Own Children
A child under 18 years who is a son or daughter by birth, a stepchild, or an adopted child of the householder is included in the own children category.

Related Children
Any child under 18 years old who is related to the householder by birth, marriage, or adoption is included in the related children category. Children, by definition, exclude persons under 18 years who maintain households or are spouses or unmarried partners of householders.

Other Relatives
In tabulations, the category other relatives includes any household member related to the householder by birth, marriage, or adoption but not included specifically in another relationship category. In certain detailed tabulations, the following categories may be shown:


Grandchild
The grandson or granddaughter of the householder.

Brother/Sister
The brother or sister of the householder, including stepbrothers, stepsisters, and brothers and sisters by adoption. Brothers-in-law and sisters-in-law are included in the Other Relative category on the questionnaire.

Parent
The father or mother of the householder, including a stepparent or adoptive parent. Fathers-in-law and mothers-in-law are included in the Parent-in-law category on the questionnaire.

Parent-in-Law
The mother-in-law or father-in-law of the householder.

Son-in-law or Daughter-in-Law
The spouse of the child of the householder.

Other Relatives
Anyone not listed in a reported category above who is related to the householder by birth, marriage, or adoption (brother-in-law, grandparent, nephew, aunt, cousin, and so forth).

Nonrelatives
This category includes any household member not related to the householder by birth, marriage, or adoption. The following categories may be presented in more detailed tabulations:

Roomer or Boarder
A roomer or boarder is a person who lives in a room in the household of the householder. Some sort of cash or noncash payment (e.g., chores) is usually made for their living accommodations.

Housemate or Roommate
A housemate or roommate is a person aged 15 years and over who is not related to the householder and who shares living quarters primarily in order to share expenses.

Unmarried Partner
An unmarried partner is a person aged 15 years and over who is not related to the householder, who shares living quarters, and who has a close personal relationship with the householder. Responses of same-sex spouse are edited into this category.

Other Nonrelatives
Anyone who is not related by birth, marriage, or adoption to the householder and who is not described by the categories given above. Unrelated foster children or unrelated foster adults are included in this category, Other Nonrelatives. A foster child who has been adopted by the householder is classified as an adopted child.

When relationship is not reported for an individual, it is allocated according to the responses for age and sex for that person while maintaining consistency with responses for other individuals in the household. (For more information on allocation, see 2010 Census: Operational Overview and Accuracy of the Data.)

Families
Family Type
A family consists of a householder and one or more other people living in the same household who are related to the householder by birth, marriage, or adoption. All people in a household who are related to the householder are regarded as members of his or her family. A family household may contain people not related to the householder, but those people are not included as part of the householders family in tabulations. Thus, the number of family households is equal to the number of families, but family households may include more members than do families. A household can contain only one family for purposes of tabulations. Not all households contain families since a household may be comprised of a group of unrelated people or of one person living alone-these are called nonfamily households. Same-sex unmarried partner households are included in the family households category only if there is at least one additional person related to the householder by birth or adoption. Families are classified by type as either a husband-wife family or other family according to the sex of the householder and the presence of relatives. The data on family type are based on answers to questions on sex and relationship.

Husband-Wife Family
A family in which the householder and his or her spouse of the opposite sex are enumerated as members of the same household.   Other Family:
  • Male householder, no wife present- A family with a male householder and no wife of householder present.
  • Female householder, no husband present- A family with a female householder and no husband of householder present.


Average Family Size
Average family size is a measure obtained by dividing the number of people in families by the total number of families (or family householders). In cases where the measures people in family or people per family are cross-tabulated by race or Hispanic origin, the race or Hispanic origin refers to the householder rather than the race or Hispanic origin of each individual. Nonrelatives of the householder living in family households are not counted as part of the family. They are included in the count of average household size. Average family size is rounded to the nearest hundredth.

Multigenerational Household
A multigenerational household is one that contains three or more parent-child generations; for example, the householder, child of householder (either biological, stepchild, or adopted child), and grandchildren of householder. A householder with a parent or parent-in-law of the householder and a child of the householder may also be a multigenerational household.

Unmarried-Partner Household
An unmarried-partner household is a household other than a "husband-wife household" that includes a householder and an unmarried partner. An "unmarried partner" can be of the same sex or of the opposite sex as the householder. An "unmarried partner" in an "unmarried-partner household" is an adult who is unrelated to the householder but shares living quarters and has a close personal relationship with the householder. An "unmarried-partner" household also may be a family household or a nonfamily household, depending on the presence or absence of another person in the household who is related to the householder. There may be only one unmarried partner per household, and an unmarried partner may not be included in a husband-wife household, as the householder cannot have both a spouse and an unmarried partner. Same-sex married-couple households are edited into this category.

Comparability
The 2000 relationship category "Natural-born son/daughter" has been replaced by "Biological son or daughter" for 2010. The category "Foster child" was dropped due to space limitations on the 2010 questionnaire. Foster children in 2010 are included in the category "Other nonrelatives." They cannot be tabulated separately. The term "married-couple" family in tabulations has been replaced by "husband-wife" family. In all standard 2010 tabulations, the term spouse refers to only a person who is married to and living with the householder and is of the opposite sex. Data for unmarried partners are comparable to data presented in 2000. Data on same-sex couple households will be presented for the first time in a special product.

Institutionalized Population
See "Group Quarters."

Noninstitutionalized Population
See "Group Quarters."

The data on race were derived from answers to the question on race that was asked of all people. The U.S. Census Bureau collects race data in accordance with guidelines provided by the U.S. Office of Management and Budget (OMB), and these data are based on self-identification. The racial categories included in the census questionnaire generally reflect a social definition of race recognized in this country and not an attempt to define race biologically, anthropologically, or genetically. In addition, it is recognized that the categories of the race item include racial and national origin or sociocultural groups. People may choose to report more than one race to indicate their racial mixture, such as American Indian and White. People who identify their origin as Hispanic, Latino, or Spanish may be any race.

The racial classifications used by the Census Bureau adhere to the October 30, 1997, Federal Register notice entitled, Revisions to the Standards for the Classification of Federal Data on Race and Ethnicity issued by OMB. These standards govern the categories used to collect and present federal data on race and ethnicity. OMB requires five minimum categories (White, Black or African American, American Indian or Alaska Native, Asian, and Native Hawaiian or Other Pacific Islander) for race. The race categories are described below with a sixth category, Some Other Race, added with OMB approval. In addition to the five race groups, OMB also states that respondents should be offered the option of selecting one or more races.

If an individual did not provide a race response, the race or races of the householder or other household members were imputed using specific rules of precedence of household relationship. For example, if race was missing for a natural-born child in the household, then either the race or races of the householder, another natural-born child, or spouse of the householder were allocated.

If race was not reported for anyone in the household, then their race was imputed based on their prior census record (either from Census 2000 or the American Community Survey), if available. If not, then the race or races of a householder in a previously processed household were allocated.

Definitions from OMB guide the Census Bureau in classifying written responses to the race question:

A person having origins in any of the original peoples of Europe, the Middle East, or North Africa. It includes people who indicate their race as White or report entries such as Irish, German, Italian, Lebanese, Arab, Moroccan, or Caucasian.

Black or African American
A person having origins in any of the Black racial groups of Africa. It includes people who indicate their race as Black, African Am., or Negro or report entries such as African American, Kenyan, Nigerian, or Haitian.

American Indian or Alaska Native
A person having origins in any of the original peoples of North and South America (including Central America) and who maintains tribal affiliation or community attachment. This category includes people who indicate their race as American Indian or Alaska Native or report entries such as Navajo, Blackfeet, Inupiat, Yupik, or Central American Indian groups or South American Indian groups.

Respondents who identified themselves as American Indian or Alaska Native were asked to report their enrolled or principal tribe. Therefore, tribal data in tabulations reflect the written entries reported on the questionnaires. Some of the entries (for example, Metlakatla Indian Community and Umatilla) represent reservations or a confederation of tribes on a reservation. The information on tribe is based on self-identification and, therefore, does not reflect any designation of federally or state-recognized tribe. The information for the 2010 Census was derived from the American Indian and Alaska Native Tribal Classification List for Census 2000 and updated from 2002 to 2009 based on the annual Federal Register notice entitled Indian Entities Recognized and Eligible to Receive Services From the United States Bureau of Indian Affairs, Department of the Interior, Bureau of Indian Affairs, issued by OMB, and through consultation with American Indian and Alaska Native communities and leaders.
The American Indian categories shown in Summary Files 1 and 2 represent tribal groupings, which refer to the combining of individual American Indian tribes, such as Fort Sill Apache, Mescalero Apache, and San Carlos Apache, into the general Apache tribal grouping.
The Alaska Native categories shown in Summary Files 1 and 2 represent tribal groupings, which refer to the combining of individual Alaska Native tribes, such as King Salmon Tribe, Native Village of Kanatak, and Sunaq Tribe of Kodiak, into the general Aleut tribal grouping.

A person having origins in any of the original peoples of the Far East, Southeast Asia, or the Indian subcontinent, including, for example, Cambodia, China, India, Japan, Korea, Malaysia, Pakistan, the Philippine Islands, Thailand, and Vietnam. It includes people who indicate their race as Asian Indian,Chinese,Filipino,Korean,Japanese,Vietnamese, and Other Asian or provide other detailed Asian responses.
    Asian Indian-Includes people who indicate their race as Asian Indian or report entries such as India or East Indian.
    Bangladeshi-Includes people who provide a response such as Bangladeshi or Bangladesh.
    Bhutanese-Includes people who provide a response such as Bhutanese or Bhutan.
    Burmese-Includes people who provide a response such as Burmese or Burma.
    Cambodian-Includes people who provide a response such as Cambodian or Cambodia.
    Chinese-Includes people who indicate their race as Chinese or report entries such as China or Chinese American. In some census tabulations, written entries of Taiwanese are included with Chinese, while in others they are shown separately.
    Filipino-Includes people who indicate their race as Filipino or report entries such as Philippines or Filipino American.
    Hmong-Includes people who provide a response such as Hmong or Mong.
    Indonesian-Includes people who provide a response such as Indonesian or Indonesia.
    Japanese-Includes people who indicate their race as Japanese or report entries such as Japan or Japanese American.
    Korean-Includes people who indicate their race as Korean or report entries such as Korea or Korean American.
Definitions of Subject Characteristics B-9U.S. Census Bureau, 2010 Census Summary File 1
    Laotian-Includes people who provide a response such as Laotian or Laos.
    Malaysian-Includes people who provide a response such as Malaysian or Malaysia.
    Nepalese-Includes people who provide a response such as Nepalese or Nepal.
    Pakistani-Includes people who provide a response such as Pakistani or Pakistan.
    Sri Lankan-Includes people who provide a response such as Sri Lankan or Sri Lanka.
    Taiwanese-Includes people who provide a response such as Taiwanese or Taiwan.
    Thai-Includes people who provide a response such as Thai or Thailand.
    Vietnamese-Includes people who indicate their race as Vietnamese or report entries such as Vietnam or Vietnamese American.
    Other Asian, specified-Includes people who provide a response of another Asian group, such as Iwo Jiman, Maldivian, Mongolian, Okinawan, or Singaporean.
    Other Asian, not specified-Includes respondents who checked the Other Asian response category on the census questionnaire and did not write in a specific group or wrote in a generic term such as Asian or Asiatic.

Native Hawaiian or Other Pacific Islander
A person having origins in any of the original peoples of Hawaii, Guam, Samoa, or other Pacific Islands. It includes people who indicate their race as Native Hawaiian,Guamanian or Chamorro,Samoan, and Other Pacific Islander or provide other detailed Pacific Islander responses.
  Native Hawaiian-Includes people who indicate their race as Native Hawaiian or report entries such as Part Hawaiian or Hawaiian.
  Samoan-Includes people who indicate their race as Samoan or report entries such as American Samoan or Western Samoan.
  Tongan-Includes people who provide a response such as Tongan or Tonga.
  Other Polynesian-Includes people who provide a response of another Polynesian group, such as Tahitian, Tokelauan, or wrote in a generic term such as Polynesian.
  Guamanian or Chamorro-Includes people who indicate their race as Guamanian or Chamorro or report entries such as Chamorro or Guam.
  Marshallese-Includes people who provide a response such as Marshallese or Marshall Islands.
  Other Micronesian-Includes people who provide a response of another Micronesian group, such as Carolinian, Chuukese, I-Kiribati, Kosraean, Mariana Islander, Palauan, Pohnpeian, Saipanese, Yapese, or wrote in a generic term such as Micronesian.
  Fijian-Includes people who provide a response such as Fijian or Fiji.
  Other Melanesian-Includes people who provide a response of another Melanesian group, such as Guinean, Hebrides Islander, Solomon Islander, or wrote in a generic term such as Melanesian.
  Other Pacific Islander, not specified-Includes respondents who checked the Other Pacific Islander response category on the census questionnaire and did not write in a specific group or wrote in a generic term such as Pacific Islander.

Some Other Race
Includes all other responses not included in the White,Black or African American,American Indian or Alaska Native,Asian, and Native Hawaiian or Other Pacific Islander race categories described above. Respondents reporting entries such as multiracial, mixed, interracial, or a Hispanic,
Latino, or Spanish group (for example, Mexican, Puerto Rican, Cuban, or Spanish) in response to the race question are included in this category.
B-10 Definitions of Subject CharacteristicsU.S. Census Bureau, 2010 Census Summary File 1

Two or More Races
People may choose to provide two or more races either by checking two or more race response check boxes, by providing multiple responses, or by some combination of check boxes and other responses. The race response categories shown on the questionnaire are collapsed into the five minimum race groups identified by OMB and the Census Bureaus Some Other Race category. For data product purposes, Two or More Races refers to combinations of two or more of the following race categories:
  1. White
  2. Black or African American
  3. American Indian or Alaska Native
  4. Asian
  5. Native Hawaiian or Other Pacific Islander
  6. Some Other Race
There are 57 possible combinations (see Figure B-1) involving the race categories shown above. Thus, according to this approach, a response of &quote;White&quote; and "Asian" was tallied as Two or More Races, while a response of Japanese and Chinese was not because Japanese and Chinese are both Asian responses.

Figure B-1. Two or More Races (57 Possible Specified Combinations)
  1. White; Black or African American
  2. White; American Indian and Alaska Native
  3. White; Asian
  4. White; Native Hawaiian and Other Pacific Islander
  5. White; Some Other Race
  6. Black or African American; American Indian and Alaska Native
  7. Black or African American; Asian
  8. Black or African American; Native Hawaiian and Other Pacific Islander
  9. Black or African American; Some Other Race
  10. American Indian and Alaska Native; Asian
  11. American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander
  12. American Indian and Alaska Native; Some Other Race
  13. Asian; Native Hawaiian and Other Pacific Islander
  14. Asian; Some Other Race
  15. Native Hawaiian and Other Pacific Islander; Some Other Race
  16. White; Black or African American; American Indian and Alaska Native
  17. White; Black or African American; Asian
  18. White; Black or African American; Native Hawaiian and Other Pacific Islander
  19. White; Black or African American; Some Other Race
  20. White; American Indian and Alaska Native; Asian
  21. White; American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander
  22. White; American Indian and Alaska Native; Some Other Race
  23. White; Asian; Native Hawaiian and Other Pacific Islander
  24. White; Asian; Some Other Race
  25. White; Native Hawaiian and Other Pacific Islander; Some Other Race
  26. Black or African American; American Indian and Alaska Native; Asian
  27. Black or African American; American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander
  28. Black or African American; American Indian and Alaska Native; Some Other Race
  29. Black or African American; Asian; Native Hawaiian and Other Pacific Islander
  30. Black or African American; Asian; Some Other Race
  31. Black or African American; Native Hawaiian and Other Pacific Islander; Some Other Race
  32. American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander
  33. American Indian and Alaska Native; Asian; Some Other Race
  34. American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander; Some Other Race
  35. Asian; Native Hawaiian and Other Pacific Islander; Some Other Race
  36. White; Black or African American; American Indian and Alaska Native; Asian
  37. White; Black or African American; American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander
  38. White; Black or African American; American Indian and Alaska Native; Some Other Race
  39. White; Black or African American; Asian; Native Hawaiian and Other Pacific Islander
  40. White; Black or African American; Asian; Some Other Race
  41. White; Black or African American; Native Hawaiian and Other Pacific Islander; Some Other Race
  42. White; American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander
  43. White; American Indian and Alaska Native; Asian; Some Other Race
  44. White; American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander; Some Other Race
  45. White; Asian; Native Hawaiian and Other Pacific Islander; Some Other Race
  46. Black or African American; American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander
  47. Black or African American; American Indian and Alaska Native; Asian; Some Other Race
  48. Black or African American; American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander; Some Other Race
  49. Black or African American; Asian; Native Hawaiian and Other Pacific Islander; Some Other Race
  50. American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander; Some Other Race
  51. White; Black or African American; American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander
  52. White; Black or African American; American Indian and Alaska Native; Asian; Some Other Race
  53. White; Black or African American; American Indian and Alaska Native; Native Hawaiian and Other Pacific Islander; Some Other Race
  54. White; Black or African American; Asian; Native Hawaiian and Other Pacific Islander; Some Other Race
  55. White; American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander; Some Other Race
  56. Black or African American; American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander; Some Other Race
  57. White; Black or African American; American Indian and Alaska Native; Asian; Native Hawaiian and Other Pacific Islander; Some Other Race


Race Concepts
Given the many possible ways of displaying data on race, data products will provide varying levels of detail. There are several additional concepts used to display race information for the six major race categories (White; Black or African American; American Indian or Alaska Native; Asian; Native Hawaiian or Other Pacific Islander; and Some Other Race) and the various details within these groups. The concept race "alone" includes people who reported a single entry (e.g., Korean) and no other race, as well as people who reported two or more entries within the same major race group (e.g., Asian). For example, respondents who reported Korean and Vietnamese are part of the larger "Asian alone" race group. The concept race alone or in combination includes people who reported a single race alone (e.g., Asian) and people who reported that race in combination with one or more of the other major race groups (e.g., White, Black or African American, American Indian and Alaska Native, Native Hawaiian and Other Pacific Islander, and Some Other Race). The concept race alone or in combination concept, therefore, represents the maximum number of people who reported as that race group, either alone or in combination with one or more additional race(s). The sum of the six individual race alone-or-in-combination categories may add to more than the total population because people who reported more than one race were tallied in each race category. The concept "race alone or in any combination" applies only to detailed race groups, such as American Indian and Alaska Native tribes, detailed Asian groups, and detailed Pacific Islander groups. For example, Korean alone or in any combination includes people who reported a single response (e.g., Korean), people who reported Korean and another Asian group (e.g., Korean and Vietnamese), and people who reported Korean in combination with one or more other non-Asian race groups (e.g., White, Black or African American, American Indian and Alaska Native, Native Hawaiian and Other Pacific Islander, or Some Other Race).

Coding of Write-In Entries
The 2010 Census included an automated review, computer edit, and coding operation on a 100 percent basis for the write-in responses to the race question, similar to that used in Census 2000. There were two types of coding operations: 1) automated coding where a write-in response was automatically coded if it matched a write-in response already contained in a database known as the master file and 2) expert coding, which took place when a write-in response did not match an entry already on the master file and was sent to expert coders familiar with the subject matter. During the coding process, subject-matter specialists reviewed and coded written entries from the response areas on the race question: American Indian or Alaska Native, Other Asian, Other Pacific Islander, and Some Other Race. Up to 30 text characters werecollected from each race write-in area, and up to two responses were coded and tabulated from each separate race write-in area.

Comparability
There are three changes to the race question for the 2010 Census. First, the note to respondents was changed to read, Please answer BOTH Question 8 about Hispanic origin and Question 9 about race. For this census, Hispanic origins are not races. Second, the wording of the race question was changed from What is this persons race? Mark ý one or more races to indicate what this person considers himself/herself to be to What is Person 1s race? Mark ý one or more boxes. Third, examples were added to the Other Asian response categories (Hmong, Laotian, Thai, Pakistani, Cambodian, and so on) and the Other Pacific Islander response categories (Fijian, Tongan, and so on). The treatment of ethnic or national origin write-in responses to the race question also was different. For Census 2000, data on single ancestry by race from the 1990 census were used to help make decisions about how to code ethnic or national origin responses into one or more race categories. Essentially, if 90 percent or more of people who reported a single, specific ancestry reported in a specific race category in 1990 (e.g., more than 90 percent of people indicating Haitian ancestry reported as Black in the question on race), then that race was used as the Census 2000 response. This 90 percent rule was not applied to write-in responses of American Indian and Alaska Native tribes, Asian groups, or Pacific Islander groups because the question on race was designed explicitly to obtain these types of responses. For example, a write-in response of Haitian and Moroccan was coded as Black and Some Other Race.Moroccan was coded as Some Other Race because less than 90 percent of people indicating Moroccan ancestry reported in one specific race category in the question on race. For the 2010 Census, ethnic or national origin write-in responses to the race question were coded into one or more of the five OMB race categories, according to the 1997 OMB definitions of race. For example, a 2010 Census write-in response of Haitian and Moroccan was coded as Black and White following OMBs definitions. If it was not possible to determine which OMB race category the ethnic group or national origin should be coded into, it was included in the Some Other Race category. For more information about comparability to data collected in previous censuses, see Census 2000 Summary File 1 Technical Documentation prepared by the U.S. Census Bureau, 2001, at www.census.gov/cen2000/doc/sf1.pdf.

Individuals were asked to mark either "male&quot or "female" to indicate their sex. For most cases in which sex was not reported, the appropriate entry was determined from the persons given (i.e., first) name and household relationship. Otherwise, sex was allocated according to the relationship to the householder and the age of the person. (For more information on allocation, see "2010 Census: Operational Overview and Accuracy of the Data.")


Sex Ratio
The sex ratio represents the balance between the male and female populations. Ratios above 100 indicate a larger male population, and ratios below 100 indicate a larger female population. This measure is derived by dividing the total number of males by the total number of females and then multiplying by 100. It is rounded to the nearest tenth.

Comparability
A question on the sex of individuals has been asked of the total population in every census.

Stepson or Stepdaughter
See "Household Type and Relationship."
Type of Institution
See "Group Quarters."

Living Quarters
Group Quarters
Group quarters are places where people live or stay in a group living arrangement, which are owned or managed by an entity or organization providing housing and/or services for the residents. This is not a typical household-type living arrangement. These services may include custodial or medical care as well as other types of assistance, and residency is commonly restricted to those receiving these services. People living in group quarters are usually not related to each other.
Group quarters include such places as college residence halls, residential treatment centers, skilled-nursing facilities, group homes, military barracks, correctional facilities, and workers dormitories.

Institutional Group Quarters
Institutional group quarters (group quarters type codes 101-106, 201-203, 301, 401-405) are facilities that house those who are primarily ineligible, unable, or unlikely to participate in the labor force while residents.


Correctional Facilities for Adults (codes 101-106)
Correctional facilities for adults include the following types:

Federal detention centers (code 101)-Federal detention centers are stand alone, generally multi-level, federally operated correctional facilities that provide short-term confinement or custody of adults pending adjudication or sentencing. These facilities may hold pretrial detainees, holdovers, sentenced offenders, and Immigration and Customs Enforcement (ICE) inmates, formerly called Immigration and Naturalization Service (INS) inmates. These facilities include Metropolitan Correctional Centers (MCCs), Metropolitan Detention Centers (MDCs), Federal Detention Centers (FDCs), Bureau of Indian Affairs Detention Centers, ICE Service Processing Centers, and ICE Contract Detention Facilities.

Federal (code 102) and state (code 103) prisons-Federal and state prisons are adult correctional facilities where people convicted of crimes serve their sentences. Common names include prison, penitentiary, correctional institution, federal or state correctional facility, and conservation camp. The prisons are classified by two types of control: 1) federal (operated by or for the Bureau of Prisons of the U.S. Department of Justice) and 2) state. Residents who are forensic patients or criminally insane are classified on the basis of where they resided at the time of enumeration. Patients in hospitals (units, wings, or floors) operated by or for federal or state correctional authorities are counted in the prison population. Other forensic patients will be enumerated in psychiatric hospital units and floors for long-term non-acute patients. This category may include privately operated correctional facilities.

Local jails and other municipal confinement facilities (code 104)-Local jails and other municipal confinement facilities are correctional facilities operated by or for counties, cities, and American Indian and Alaska Native tribal governments. These facilities hold adults detained pending adjudication and/or people committed after adjudication. This category also includes work farms and camps used to hold people awaiting trial or serving time on relatively short sentences. Residents who are forensic patients or criminally insane are classified on the basis of where they resided at the time of enumeration. Patients in hospitals (units, wings, or floors) operated by or for local correctional authorities are counted in the jail population. Other forensic patients will be enumerated in psychiatric hospital units and floors for long-term non-acute care patients. This category may include privately operated correctional facilities.

Correctional residential facilities (code 105)Correctional residential facilities are community-based facilities operated for correctional purposes. The facility residents may be allowed extensive contact with the community, such as for employment or attending school, but are obligated to occupy the premises at night. Examples of correctional residential facilities are halfway houses, restitution centers, and prerelease, work release, and study centers.
Military disciplinary barracks and jails (code 106)-Military disciplinary barracks and jails are correctional facilities managed by the military to hold those awaiting trial or convicted of crimes.


Juvenile Facilities (codes 201-203)
Juvenile facilities include the following:
Group homes for juveniles (non-correctional) (code 201)-Group homes for juveniles include community-based group living arrangements for youth in residential settings that are able to accommodate three or more clients of a service provider. The group home provides room and board and services, including behavioral, psychological, or social programs. Generally, clients are not related to the caregiver or to each other. Examples of non-correctional group homes for juveniles are maternity homes for unwed mothers, orphanages, and homes for abused and neglected children in need of services. Group homes for juveniles do not include residential treatment centers for juveniles or group homes operated by or for correctional authorities.

Residential treatment centers for juveniles (non-correctional) (code 202)-Residential treatment centers for juveniles include facilities that provide services primarily to youth on-site in a highly structured live-in environment for the treatment of drug/alcohol abuse, mental illness, and emotional/behavioral disorders. These facilities are staffed 24 hours a day. The focus of a residential treatment center is on the treatment program. Residential treatment centers for juveniles do not include facilities operated by or for correctional authorities.

Correctional facilities intended for juveniles (code 203) - Correctional facilities intended for juveniles include specialized facilities that provide strict confinement for their residents and detain juveniles awaiting adjudication, commitment or placement, and/or those being held for diagnosis or classification. Also included are correctional facilities where residents are permitted contact with the community for purposes such as attending school or holding a job. Examples of correctional facilities intended for juveniles are residential training schools and farms, reception and diagnostic centers, group homes operated by or for correctional authorities, detention centers, and boot camps for juvenile delinquents.

Nursing Facilities/Skilled-Nursing Facilities (code 301)
Nursing facilities/Skilled-nursing facilities include facilities licensed to provide medical care with 7-day, 24-hour coverage for people requiring long-term non-acute care. People in these facilities require nursing care, regardless of age. Either of these types of facilities may be referred to as nursing homes.


Other Institutional Facilities (codes 401-405)
Other institutional facilities include the following:
Mental (psychiatric) hospitals and psychiatric units in other hospitals (code 401)-Mental (psychiatric) hospitals and psychiatric units in other hospitals include psychiatric hospitals, units and floors for long-term non-acute care patients. The primary function of the hospital, unit, or floor is to provide diagnostic and treatment services for long-term non-acute patients who have psychiatric-related illness. All patients are enumerated in this category.

Hospitals with patients who have no usual home elsewhere (code 402)-Hospitals with patients who have no usual home elsewhere include hospitals that have any patients who have no exit or disposition plan, or who are known as boarder patients or boarder babies. All hospitals are eligible for inclusion in this category except psychiatric hospitals, units, wings, or floors operated by federal, state, or local correctional authorities. Patients in hospitals operated by these correctional authorities will be counted in the prison or jail population. Psychiatric units and hospice units in hospitals are also excluded. Only patients with no usual home elsewhere are enumerated in this category.
In-patient hospice facilities (both free-standing and units in hospitals) (code 403)-In-patient hospice facilities (both free-standing and units in hospitals) include facilities that provide palliative, comfort, and supportive care for terminally ill patients and their families. Only patients with no usual home elsewhere are tabulated in this category.
Military treatment facilities with assigned patients (code 404)-Military treatment facilities with assigned patients include military hospitals and medical centers with active duty patients assigned to the facility. Only these patients are enumerated in this category.

Residential schools for people with disabilities (code 405)-Residential schools for people with disabilities include schools that provide the teaching of skills for daily living, education programs, and care for students with disabilities in a live-in environment. Examples of residential schools for people with disabilities are residential schools for the physically or developmentally disabled.

Noninstitutional Group Quarters
Noninstitutional group quarters (group quarters type codes 501, 601, 602, 701, 702, 704, 706, 801, 802, 900, 901, 903, 904) are facilities that house those who are primarily eligible, able, or likely to participate in the labor force while residents.

College/University Student Housing (code 501)
College/University student housing includes residence halls and dormitories, which house college and university students in a group living arrangement. These facilities are owned, leased, or managed either by a college, university, or seminary, or by a private entity or organization. Fraternity and sorority housing recognized by the college or university are included as college student housing. However, students attending the U.S. Naval Academy, U.S. Military Academy (West Point), U.S. Coast Guard Academy, and U.S. Air Force Academy are counted in military group quarters.

Military Quarters (codes 601 and 602)
Military quarters (code 601) are facilities that include military personnel living in barracks (including "open" barrack transient quarters) and dormitories and military ships (code 602). Patients assigned to Military Treatment Facilities and people being held in military disciplinary barracks and jails are not enumerated in this category. Patients in Military Treatment Facilities with no usual home elsewhere are not enumerated in this category.

Other Noninstitutional Facilities (codes 701, 702, 704, 706, 801, 802, 900, 901, 903, and 904)
Other noninstitutional facilities include the following:
    Emergency and transitional shelters (with sleeping facilities) for people experiencing homelessness (code 701)-Emergency and transitional shelters (with sleeping facilities) for people experiencing homelessness are facilities where people experiencing homelessness stay overnight. These include:
1. Shelters that operate on a first-come, first-serve basis where people must leave in the morning and have no guaranteed bed for the next night.
2. Shelters where people know that they have a bed for a specified period of time (even if they leave the building every day).
3. Shelters that provide temporary shelter during extremely cold weather (such as churches). This category does not include shelters that operate only in the event of a natural disaster.

Examples are emergency and transitional shelters; missions; hotels and motels used to shelter people experiencing homelessness; shelters for children who are runaways, neglected, or experiencing homelessness; and similar places known to have people experiencing homelessness.

Soup kitchens, regularly scheduled mobile food vans, and targeted non-sheltered outdoor locations (codes 702, 704, and 706)-This category includes soup kitchens that offer meals organized as food service lines or bag or box lunches for people experiencing homelessness; street locations where mobile food vans regularly stop to provide food to people experiencing homelessness; and targeted non-sheltered outdoor locations where people experiencing homelessness live without paying to stay. This also would include persons staying in pre-identified car, recreational vehicle (RV), and tent encampments. Targeted non-sheltered outdoor locations must have a specific location description; for example, "the Brooklyn Bridge at the corner of Bristol Drive, " "the 700 block of Taylor Street behind the old warehouse",or the address of the parking lot being utilized.

Group homes intended for adults - (code 801)Group homes intended for adults are community-based group living arrangements in residential settings that are able to accommodate three or more clients of a service provider. The group home provides room and board and services, including behavioral, psychological, or social programs. Generally, clients are not related to the caregiver or to each other. Group homes do not include residential treatment centers or facilities operated by or for correctional authorities.

Residential treatment centers for adults (code 802) - Residential treatment centers for adults provide treatment on-site in a highly structured live-in environment for the treatment of drug/alcohol abuse, mental illness, and emotional/behavioral disorders. They are staffed 24 hours a day. The focus of a residential treatment center is on the treatment program. Residential treatment centers do not include facilities operated by or for correctional authorities.

Maritime/Merchant vessels (code 900) - Maritime/merchant vessels include U.S. owned and operated flag vessels used for commercial or noncombatant government-related purposes at U.S. ports, on the sea, or on the Great Lakes.

Workers group living quarters and Job Corps centers (code 901) - Workers group living quarters and Job Corps centers include facilities such as dormitories, bunkhouses, and similar types of group living arrangements for agricultural and non-agricultural workers. This category also includes facilities that provide a full-time, year-round residential program offering a vocational training and employment program that helps young people 16 to 24 years old learn a trade, earn a high school diploma or GED, and get help finding a job. Examples are group living quarters at migratory farm-worker camps, construction workers camps, Job Corps centers, and vocational training facilities.

Living quarters for victims of natural disasters (code 903) - Living quarters for victims of natural disasters are temporary group living arrangements established as a result of natural disasters.

Religious group quarters and domestic violence shelters (code 904)-Religious group quarters are living quarters owned or operated by religious organizations that are intended to house their members in a group living situation. This category includes such places as convents, monasteries, and abbeys. Living quarters for students living or staying in seminaries are classified as college student housing, not religious group quarters. Domestic violence shelters are community-based homes, shelters, or crisis centers that provide housing for people who have sought shelter from household violence and who may have been physically abused.

Comparability
Due to the consolidation of group quarters types and general streamlining of the definitions, several changes have been implemented in the 2010 Census group quarters definitions and type codes that are reflected in 2010 Census data products.

As in Census 2000, group quarters are either institutional group quarters or noninstitutional group quarters.

Institutional group quarters are facilities that house those who are primarily ineligible, unable, or unlikely to participate in the labor force while residents. This definition has been simplified since the 1990 and 2000 Censuses (both used the same definition, which focused on institutions providing formally authorized, supervised care or custody) to focus on labor force participation.

The phrase institutionalized persons in the 1990 Census data was changed to institutionalized population in Census 2000 and continues in the 2010 Census.

Correctional facilities for adults - In the 2010 Census data products, the Census 2000 term other type of correctional institutions is categorized as "correctional residential facilities."

Juvenile facilities - Those group quarters categorized as "homes for abused, dependent, and neglected children" (public, private, or ownership unknown) in the Census 2000 data products are categorized as group homes for juveniles (non-correctional) in the 2010 Census data products. Those categorized in training schools (public, private, and ownership unknown), detention centers, reception or diagnostic centers, and type of juvenile institution unknown in Census 2000 data products are categorized in the 2010 Census data products as correctional facilities intended for juveniles (i.e., training schools and farms, reception and diagnostic centers, detention centers, boot camps and group homes operated by or for correctional authorities).

Nursing facilities/skilled-nursing facilities - In the 2010 Census data products, all nursing homes are categorized as "nursing facilities/skilled-nursing facilities.quot;
Other institutional facilities - Those group quarters categorized as schools, hospitals, or wards for the physically handicapped in Census 2000 data products are categorized as "residential schools for people with disabilities" in the 2010 Census data products. "Military hospitals or wards for chronically ill are classified as military treatment facilities with assigned patients in the 2010 Census data products. Also, what were called military hospitals with patients who have no usual home elsewhere in Census 2000 data products are categorized as hospitals with patients who have no usual home elsewhere in 2010 Census data products. Hospices or homes for the chronically ill or other hospitals or wards for chronically ill are categorized in the 2010 Census data products as in-patient hospice facilities.Hospitals and wards for drug/alcohol abuse and mentally ill (psychiatric) hospitals or wards are categorized in the 2010 Census data products as mental (psychiatric) hospitals and psychiatric units in other hospitals.

The phrase staff residents was used for staff living in institutions in both the 1990 and 2000 Censuses. In Census 2000, staff living in institutions included those living in agricultural workers dormitories,other workers dormitories,Job Corps and vocational training facilities,dormitories for nurses and interns in military hospitals, and dormitories for nurses and interns in general hospitals. In the 2010 Census, all these groups are categorized as workers group living quarters and Job Corps centers.

Noninstitutional group quarters - In the 1990 Census, the Census Bureau used the phrase other persons in group quarters for people living in noninstitutionalized group quarters. In 2000, this group was referred to for the first time as the noninstitutionalized population. In 2010, this population continues to be referred to as the noninstitutionalized population. Noninstitutional group quarters are facilities that house those who are primarily eligible, able, or likely to participate in the labor force while a resident.

As of Census 2000, the Census Bureau dropped the rule of classifying ten or more unrelated people living together as living in noninstitutional group quarters. This rule was used in the 1990 and 1980 Censuses. In the 1970 Census, the criteria was six or more unrelated people.

College/University student housing - In the 2010 Census, residence halls and dormitories, which house college and university students in a group living arrangement, may be owned, leased, or managed either by a college, university, or seminary or by a private entity or organization. In Census 2000, these types of facilities had to be owned by the college or university.

Military quarters - In 1960 data products, people in military barracks were shown only for men. Starting in 1970 and to the present, data are available for both men and women in military barracks. What were classified as transient quarters for temporary residents (military or civilian)" in Census 2000 data products no longer include the civilian population, and the military residents are tabulated in "military quarters" in 2010 Census data products.

Other noninstitutional facilities- In the 2010 Census, "workers group living quarters and Job Corps centers" are comprised of the following Census 2000 group quarters types: "agriculture workers" dormitories," "other workers" dormitories," "Job Corps and vocational training facilities," and "dormitories for nurses and interns in hospitals (general and military)." As in Census 2000 and also in 1990, workers dormitories were classified as group quarters regardless of the number of people sharing the dormitory. In 1980, ten or more unrelated people had to share the dorm for it to be classified as a group quarters.
In the 2010 Census, "emergency and transitional shelters (with sleep facilities) for people experiencing homelessness" includes the Census 2000 categories "emergency and transitional shelters" and "shelters for children who are runaways, neglected, or without conventional housing."
In the 2010 Census, "religious group quarters" are combined with "shelters for abused women (or shelters against domestic violence)" to make the category "religious group quarters and domestic violence shelters."
In the 2010 Census data products, the category "group homes intended for adults (non-correctional)" consists of the following group quarters types (as listed in Census 2000): homes for the mentally ill," "homes for the mentally retarded," "homes for the physically handicapped," "residential care facilities providing protective oversight," and "other group homes." "Homes or halfway houses for drug/alcohol abuse" are categorized as "residential treatment centers for adults (non-correctional)."
The following group quarters types that were included in Census 2000 are no longer classified as group quarters in the 2010 Census: "military hotels/campgrounds," " transient locations," and "other household living situations ' -dangerous encampments."
Like in Census 2000, rooming and boarding houses are classified as housing units in the 2010 Census. In the 1990 Census, these were considered group quarters.

Housing Units
A housing unit is a living quarters in which the occupant or occupants live separately from any other individuals in the building and have direct access to their living quarters from outside the building or through a common hall. Housing units are usually houses, apartments, mobile homes, groups of rooms, or single rooms that are occupied as separate living quarters. They are residences for single individuals, groups of individuals, or families who live together. A single individual or a group living in a housing unit is defined to be a household. Additional details about housing for the elderly population and group homes are provided in the section Housing for the Older Population.

For vacant housing units, the criteria of separateness and direct access are applied to the intended occupants whenever possible. Nontraditional living quarters such as boats, RVs, and tents are considered to be housing units only if someone is living in them and they are either the occupants usual residence or the occupant has no usual residence elsewhere. These nontraditional living arrangements are not considered to be housing units if they are vacant. Housing units are classified as being either occupied or vacant.

Occupied Housing Unit
A housing unit is classified as occupied if it is the usual place of residence of the individual or group of individuals living in it on Census Day, or if the occupants are only temporarily absent, such as away on vacation, in the hospital for a short stay, or on a business trip, and will be returning.
The occupants may be an individual, a single family, two or more families living together, or any other group of related or unrelated individuals who share living arrangements.
Occupied rooms or suites of rooms in hotels, motels, and similar places are classified as housing units only when occupied by permanent residents; that is, occupied by individuals who consider the hotel their usual place of residence or who have no usual place of residence elsewhere. However, when rooms in hotels and motels are used to provide shelter for people experiencing homelessness, they are not housing units. Rooms used in this way are considered group quarters.

Vacant Housing Unit
A housing unit is classified as vacant if no one is living in it on Census Day, unless its occupant or occupants are only temporarily absent-such as away on vacation, in the hospital for a short stay, or on a business trip-and will be returning.

Housing units temporarily occupied at the time of enumeration entirely by individuals who have a usual residence elsewhere are classified as vacant. When housing units are vacant, the criteria of separateness and direct access are applied to the intended occupants whenever possible. If that information cannot be obtained, the criteria are applied to the previous occupants.

Boats, RVs, tents, caves, and similar shelter that no one is using as a usual residence are not considered living quarters and therefore are not enumerated at all.

Housing for the Older Population
Housing specifically for the older population has become more and more prevalent and is being identified by many different names. Living quarters in these facilities, unless they meet the definition of skilled nursing facilities, are housing units, with each residents living quarters considered a separate housing unit if it meets the housing unit definition of direct access. These residential facilities may be referred to as senior apartments, active adult communities, congregate care, continuing care retirement communities, independent living, board and care, or assisted living. People may have to meet certain criteria to be able to live in these facilities, but once accepted as residents they have unrestricted access to and from their units to the outside.

Housing units and group quarters may coexist under the same entity or organization and in some situations, actually share the same structure. An assisted living facility complex may have a skilled nursing floor or wing that meets the definition of a nursing facility and is, therefore, a group quarters, while the rest of the living quarters in the facility are considered to be housing units. Congregate care facilities and continuing care retirement communities often consist of several different types of living quarters, with varying services and levels of care. Some of the living quarters in these facilities and communities are considered to be housing units and some are considered to be group quarters, depending on which definition they meet.

Comparability
The first Census of Housing in 1940 established the dwelling unit concept. Although the term became housing unit and the definition was modified slightly in succeeding censuses, the housing unit definition remained essentially comparable between 1940 and 1990. Since 1990, two changes were made to the housing unit definition.
The first change eliminated the concept of eating separately. The elimination of the eating criterion is more in keeping with the United Nations definition of a housing unit that stresses the entire concept of separateness rather than the specific eating element. Although the eating separately criterion previously was included in the definition of a housing unit, the data needed to distinguish whether the occupants ate separately from any other people in the building were not collected. (Questions that asked households about their eating arrangements have not been included in the census since 1970.) Therefore, the current definition better reflects the information that is used in the determination of a housing unit.

The second change for Census 2000 and the 2010 Census eliminated the number of nonrelatives criterion; that is, 9 or more people unrelated to the householder which caused a conversion of housing units to group quarters. This change was prompted by the following considerations: 1) there were relatively few such conversions made as a result of this rule in 1990; 2) household relationship and housing data were lost by converting these units to group quarters; and 3) there was no empirical support for establishing a particular number of nonrelatives as a threshold for these conversions.

In 1960, 1970, and 1980, vacant rooms in hotels, motels, and other similar places where 75 percent or more of the accommodations were occupied by permanent residents were counted as part of the housing inventory. However, an evaluation of the data collection procedures prior to the 1990 Census indicated that the concept of permanency was a difficult and confusing procedure for enumerators to apply correctly. Consequently, in the 1990 Census, vacant rooms in hotels, motels, and similar places were not counted as housing units. In Census 2000 and the 2010 Census, we continued the procedure adopted in 1990.


Housing Characteristics
Household Size
This question is based on the count of people in occupied housing units. All people occupying the housing unit are counted, including the householder, occupants related to the householder, and lodgers, roomers, boarders, and so forth.

Average Household Size of Occupied Unit
The average household size of an occupied unit is a measure obtained by dividing the number of people living in occupied housing units by the total number of occupied housing units. This measure is rounded to the nearest hundredth.
Average Household Size of Owner-Occupied Unit
The average household size of an owner-occupied unit is a measure obtained by dividing the number of people living in owner-occupied housing units by the total number of owner-occupied housing units. This measure is rounded to the nearest hundredth.
Average Household Size of Renter-Occupied Unit
The average household size of a renter-occupied unit is a measure obtained by dividing the number of people living in renter-occupied housing units by the total number of renter-occupied housing units. This measure is rounded to the nearest hundredth.

Tenure
Tenure was asked at all occupied housing units. All occupied housing units are classified as either owner-occupied or renter-occupied.

Owner-Occupied
A housing unit is owner-occupied if the owner or co-owner lives in the unit even if it is mortgaged or not fully paid for. The owner or co-owner must live in the unit and usually is Person 1 on the questionnaire. The unit is Owned by you or someone in this household with a mortgage or loan if it is being purchased with a mortgage or some other debt arrangement, such as a deed of trust, trust deed, contract to purchase, land contract, or purchase agreement. The unit is also considered owned with a mortgage if it is built on leased land and there is a mortgage on the unit.

A housing unit is Owned by you or someone in this household free and clear (without a mortgage or loan) if there is no mortgage or other similar debt on the house, apartment, or mobile home, including units built on leased land if the unit is owned outright without a mortgage. Although most tables show total owner-occupied counts, selected tables separately identify the two owner categories.

Renter-Occupied
All occupied housing units which are not owner-occupied, whether they are rented or occupied without payment of rent, are classified as renter-occupied. Rented includes units in continuing care, sometimes called life care arrangements. These arrangements usually involve a contract between one or more individuals and a service provider guaranteeing the individual shelter, usually an apartment, and services, such as meals or transportation to shopping or recreation. The no rent paid category includes units provided free by friends or relatives or in exchange for services, such as a resident manager, caretaker, minister, or tenant farmer. Housing units on military bases are also classified in the No rent paid category.

Comparability
Data on tenure have been collected since 1890. In 1990, the response categories were expanded to allow the respondent to report whether the unit was owned with a mortgage or loan, or free and clear (without a mortgage). The distinction between units owned with a mortgage and units owned free and clear was added in 1990 to improve the count of owner-occupied units. Research after the 1980 Census indicated some respondents did not consider their units owned if they had a mortgage. In Census 2000, we continued with the same tenure categories used in the 1990 Census. In 2010, the instruction Include home equity loans was added following the response category Owned by you or someone in this household with a mortgage or loan? Additional changes included revising the wording of two response categories from Rented for cash rent? to Rented? and Occupied without payment of cash rent? to Occupied without payment of rent?

Vacancy Status
The data on vacancy status were obtained from Enumerator Questionnaire item C. Vacancy status and other characteristics of vacant units were determined by census enumerators obtaining information from landlords, owners, neighbors, rental agents, and others. Vacant units are subdivided according to their housing market classification as follows:

    For Rent - These are vacant units offered for rent and vacant units offered either for rent or for sale.
    Rented, Not Occupied - These are vacant units rented but not yet occupied, including units where money has been paid or agreed upon, but the renter has not yet moved in.
    For Sale Only - These are vacant units being offered for sale only, including units in cooperatives and condominium projects if the individual units are offered for sale only. If units are offered either for rent or for sale, they are included in the for rent classification.
    Sold, Not Occupied - These are vacant units sold but not yet occupied, including units that have been sold recently, but the new owner has not yet moved in.
    For Seasonal, Recreational, or Occasional Use - These are vacant units used or intended for use only in certain seasons or for weekends or other occasional use throughout the year. Seasonal units include those used for summer or winter sports or recreation, such as beach cottages and hunting cabins. Seasonal units also may include quarters for such workers as herders and loggers. Interval ownership units, sometimes called shared-ownership or time-sharing condominiums, also are included here.
    For Migrant Workers - These include vacant units intended for occupancy by migratory workers employed in farm work during the crop season. (Work in a cannery, freezer plant, or food-processing plant is not farm work.)
    Other Vacant - If a vacant unit does not fall into any of the categories specified above, it is classified as Other vacant. For example, this category includes units held for occupancy by a caretaker or janitor and units held for personal reasons of the owner.
    Homeowner Vacancy Rate - The homeowner vacancy rate is the proportion of the homeowner inventory that is vacant for sale. It is computed by dividing the number of vacant units for sale only by the sum of the owner-occupied units, vacant units that are for sale only, and vacant units that have been sold but not yet occupied, and then multiplying by 100. This measure is rounded to the nearest tenth.
    Rental Vacancy Rate - The rental vacancy rate is the proportion of the rental inventory that is vacant for rent. It is computed by dividing the number of vacant units for rent by the sum of the renter-occupied units, vacant units that are for rent, and vacant units that have been rented but not yet occupied, and then multiplying by 100. This measure is rounded to the nearest tenth.
    Available Housing Vacancy Rate - The available housing vacancy rate is the proportion of the housing inventory that is vacant-for-sale only and vacant-for-rent. It is computed by dividing the sum of vacant-for-sale-only housing units and vacant-for-rent housing units, by the sum of occupied units, vacant-for-sale-only housing units, vacant-sold-not-occupied housing units, vacant-for-rent housing units, and vacant-rented-not-occupied housing units, and then multiplying by 100. This measure is rounded to the nearest tenth.
    Comparability - Data on vacancy status have been collected since 1940. Since 1990, we have used the category For seasonal, recreational, or occasional use. In earlier censuses, separate categories were used to collect data on these types of vacant units. Also, in 1970 and 1980, housing characteristics generally were presented only for year-round units. Beginning in 1990 and continuing into Census 2000, housing characteristics are shown for all housing units. Census 2000 used a single vacancy status category for units that were either Rented or sold, not occupied. In 2010, we used two separate categories Rented, not occupied and Sold, not occupied. This change provided consistency with the American Community Survey and the Housing Vacancy Survey. These revised categories were incorporated in the calculations of the homeowner vacancy, rental vacancy, and the available housing vacancy rates.


Derived Measures
Census data products include various derived measures, such as medians, means, and percentages, as well as certain rates and ratios. Derived measures that round to less than 0.1 are not shown but indicated as zero.
Average
See "Mean."
Interpolation
Interpolation is frequently used to calculate medians or quartiles and to approximate standard errors from tables based on interval data. Different kinds of interpolation may be used to estimate the value of a function between two known values, depending on the form of the distribution. The most common distributional assumption is that the data are linear, resulting in linear interpolation.
This measure represents an arithmetic average of a set of values. It is derived by dividing the sum (or aggregate) of a group of numerical items by the total number of items in that group. For example, average family size is obtained by dividing the number of people in families by the total number of families (or family householders). (Additional information on means and aggregates is included in the separate explanations of many of the population and housing subjects.)
Median
This measure represents the middle value (if n is odd) or the average of the two middle values (if n is even) in an ordered list of n data values. The median divides the total frequency distribution into two equal parts: one-half of the cases falling below the median and one-half above the median. Each median is calculated using a standard distribution. The standard distribution for the calculation of median age is:

Age [116]

  Under 1 year
  1 year
  2 years
  3 years
  4 years
  5 years
  .
  .
  .
  112 years
  113 years
  114 years
  115 years and over

(For more information, see "Interpolation.")
Jam values will be assigned whenever the median falls in an open-ended interval. For example, if the median age value fell in the open-ended category 115 years and over, the value displayed would be 115+. The presentation of jam values will vary between products and types of media.
For data products displayed in American FactFinder, publications, or in display table format, medians that fall in the upper-most category of an open-ended distribution will be shown with a plus symbol (+) appended, and medians that fall in the lowest category of an open-ended distribution will be shown with a minus symbol (-) appended. For other data products and data files that are downloaded by users (i.e., FTP files), plus and minus signs will not be appended.
Percentage
This measure is calculated by taking the number of items in a group possessing a characteristic of interest and dividing by the total number of items in that group, and then multiplying by 100.
This is a measure of occurrences in a given period of time divided by the possible number of occurrences during that period. For example, the homeowner vacancy rate is calculated by dividing the number of vacant units for sale only by the sum of owner-occupied units, vacant units that are for sale only, and vacant units that have been sold but not yet occupied, and then multiplying by 100. Rates are sometimes presented as percentages.