Technical Note The estimates in this release are based on annual average data from the Current Population Survey (CPS). The CPS, which is conducted by the U.S. Census Bureau for the Bureau of Labor Statistics (BLS), is a monthly survey of about 60,000 eligible households that provides information on the labor force status, demographics, and other characteristics of the nation's civilian noninstitutional population age 16 and over. If you are deaf, hard of hearing, or have a speech disability, please dial 7-1-1 to access telecommunications relay services. Definitions Definitions of the principal terms used in this release are described briefly below. Householder. The householder is the family reference person. This is the person (or one of the persons) in whose name the housing unit is owned or rented. The relationship of other individuals in the household is defined in terms of their relationship to the householder. The race and Hispanic ethnicity of the family is determined by that of the householder. Family. A family is a group of two or more persons residing together who are related by birth, marriage, or adoption; all such individuals are considered members of one family. The count of families is for "primary" families only. A primary family consists of a householder and all other persons related to and residing with the householder. Sub-families are excluded from the count of families. A sub-family is a family that does not maintain their own household, such as a married couple living in the home of a friend and their family. In this example, the report would include only one family (the householder's or primary family), not two. Families include those with and without children under age 18. Families are further categorized as follows: --Married-couple families refer to opposite-sex and same-sex married couples residing together and any of their family members residing in the household. --Families maintained by women or men are made up of householders residing with one or more family members but no spouse of either sex present. Unmarried domestic partners of either sex may or may not be present in the household. This release presents data for two marital status categories, defined below. Marital status is based on a person's status at the time of the survey. Total married, spouse present. Married, spouse present, includes persons in either opposite-sex or same-sex marriages living together in the same household, even though one may be temporarily absent on business, on vacation, on a visit, in a hospital, or for other reasons. Other marital status. Other marital status includes persons who are never married; widowed; divorced; separated; and married, spouse absent. Separated includes persons with legal separations, those living apart with intentions of obtaining a divorce, and other persons permanently or temporarily separated because of marital discord. Married, spouse absent, includes married persons living apart because either a husband or wife was employed and living at a considerable distance from home, was serving away from home in the Armed Forces, had moved to another area, or had a different place of residence for any other reason except separation as defined above. Children. Data on children refer to own children under age 18 that live in the household. Included are biological, step-, and adopted children of the husband, wife, or person maintaining the family. Not included are nieces, nephews, grandchildren, other related children, and all unrelated children living in the household. Children not living in the household are also not included. Employed. Employed persons are all those who, during the survey reference week, (a) did any work at all as paid employees; (b) worked in their own business, profession, or on their own farm; or (c) worked 15 hours or more as unpaid workers in an enterprise operated by a member of the family. Persons who were temporarily absent from their jobs because of illness, vacation, labor disputes, or another reason also are counted as employed. Full-time workers. Full-time workers are those who usually work 35 hours or more per week at all jobs. Part-time workers. Part-time workers are those who usually work fewer than 35 hours per week at all jobs. Unemployed. The unemployed are persons who had no employment during the reference week, were available for work at that time, and had made specific efforts to find employment sometime during the 4-week period ending with the reference week. Persons who were waiting to be recalled to a job from which they had been laid off need not be looking for work to be classified as unemployed. Civilian labor force. The civilian labor force comprises all persons classified as employed or unemployed. Labor force participation rate. The labor force participation rate is the number of persons in the labor force as a percent of the population. Employment-population ratio. The employment-population ratio is the number of employed persons as a percent of the population. Unemployment rate. The unemployment rate is the number of unemployed persons as a percent of the civilian labor force. Reliability of the estimates Statistics based on the CPS are subject to both sampling and nonsampling error. When a sample, rather than the entire population, is surveyed, there is a chance that the sample estimates may differ from the true population values they represent. The exact difference, or sampling error, varies depending on the particular sample selected, and this variability is measured by the standard error of the estimate. There is about a 90-percent chance, or level of confidence, that an estimate based on a sample will differ by no more than 1.6 standard errors from the true population value because of sampling error. BLS analyses are generally conducted at the 90-percent level of confidence. The CPS data also are affected by nonsampling error. Nonsampling error can occur for many reasons, including the failure to sample a segment of the population, inability to obtain information for all respondents in the sample, inability or unwillingness of respondents to provide correct information, and errors made in the collection or processing of the data. Information about the reliability of data from the CPS and guidance on estimating standard errors are available at www.bls.gov/cps/documentation.htm#reliability. Comparability of the estimates Effective with data for 2020, estimates of the number of married persons refer to those in opposite-sex and same-sex marriages. Prior to 2020, estimates of the number of married persons referred to those in opposite-sex marriages only. The definition of families incorporated this change by expanding the definition of married-couple families to include same-sex married couples. This new classification resulted in a larger estimate of the number of persons who are married with a spouse present. It also resulted in a larger estimate of the number of married-couple families and the total number of families. The 2019 estimates mentioned in this news release are revised data that incorporate the new classification of married persons. These revised 2019 estimates, as published in the "Employment Characteristics of Families--2020" news release, do not match those originally published in the "Employment Characteristics of Families--2019" news release or in the BLS online database. Additional information about the classification change is available from the Census Bureau at www.census.gov/content/dam/Census/library/working-papers/2019/demo/SEHSD-WP-2018-30.pdf. In addition, the data presented in this release are not strictly comparable with data for earlier years due to the introduction of updated population estimates, or controls, used in the CPS. The population controls are updated each year in January to reflect the latest information about population change. Additional information is available from the BLS website at www.bls.gov/cps/documentation.htm#pop.