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.

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.

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.