Glossary

In the ACS, a person is defined as actively looking for work if they report looking for work during the last 4 weeks.

In the ACS, ambulatory disability is based on the question (asked of persons age 5 or older): Does this person have serious difficulty walking or climbing stairs?

The American Community Survey (ACS) is a continuous data collection effort by the US Census Bureau. The data is used to produce annual estimates at the national, state, and local level on the characteristics of the United States population. The ACS is sent to a sample of approximately 3.5  million addresses in the United States, 2.5% of the population living in group quarters, and 36,000 addresses in Puerto Rico.

The survey asks about age, sex, race, family and relationships, income and benefits, health insurance, education, veteran status, disabilities, and more. See Disability and Disability Types - ACS.

The base population is the estimated number of individuals upon which a calculation is based. (For percentages, this is the denominator.)

The Behavioral Risk Factor Surveillance System is a US Centers for Disease Control and Prevention (CDC) survey. It is designed to monitor risk behaviors related to chronic diseases, injuries and death; identify emerging health problems; establish and track health objectives; and develop and evaluate public health policies and programs.

Conducted annually as a cross-sectional, telephone-based survey of adults ages 18 and older, it provides national, state, and selected county and MSA level data on health risk behaviors, preventive health practices, and health care access primarily related to chronic disease and injury.

The civilian population is the portion of the resident population not in the active-duty military.

Class of Worker is one of the Work Characteristics collected by the ACS. Class of Worker has nine categories for the type of ownership of the person’s employing organization:

The confidence interval describes the level of uncertainty of an estimate of a population and specifies the range in which the true value is likely to fall. Because the estimate is based upon a sample rather than observations from the entire population, there is a degree of uncertainty associated with the description of the population.

The confidence interval calculated on DisabilityStatistics.org is based on a 95% level of significance, which means there is a 95 percent chance that the true value falls within these boundaries. The lower bound is calculated by subtracting the confidence interval from the population estimate and the upper bound is calculated by adding the confidence interval to the estimate.

An example from the 2002 CPS work-limitation prevalence rate:

  • Year: 2002
  • Number: 13,474,000
  • Confidence Interval: ± 26,000
  • Sample Size: 128,588,000

In the year 2002, an estimated 13,474,000 out of 174,869,000 (or about one in 13) civilian, non-institutionalized men and women aged 18–64 in the United States reported a work limitation. The confidence interval shows that with 95% certainty the actual population value falls within the range of 26,000 below and 26,000 above the estimate of 13,474,000.

In the United States, each state is divided into congressional districts (CDs). Registered voters within each district elect a representative to the US House of Representatives. Within each state, each CD is supposed to have the same number of people within it as is practicable, based on the Decennial Census. The number of districts in a state may change after each decennial census, and the boundaries may be changed more than once during a decade.

The District of Columbia and Puerto Rico each have a single CD for the entire area. This representative is called a delegate or resident commissioner, respectively, and does not have voting rights in Congress.

The Current Population Survey (CPS) is a monthly survey of the non-institutionalized population of the United States. Information is collected on labor force characteristics, such as employment, earnings, and hours of work.

In March of each year, the CPS Basic Monthly Survey is fielded with the Annual Social and Economic Supplement. This supplement focuses on sources of income, government program participation, previous employment, insurance, and a variety of demographic characteristics. The CPS and the Annual Social and Economic Supplement are used extensively by government agencies, researchers, policymakers, journalists, and the general public to evaluate government programs, economic well-being, and behavior of individuals, families, and households.

The US Census Bureau conducts the CPS and the Annual Social and Economic Supplement on behalf of the US Bureau of Labor Statistics. The CPS surveys the resident population of the United States; citizens living abroad are not surveyed. Those in long-term care facilities are also excluded. Currently, approximately 200,000 individuals participate in the surveys annually.

CPS timeline:

  • 1940s: CPS begins.
  • 1981: Work-limitation variable introduced.
  • 1994: Major revisions were made to the employment questions on the Basic Monthly Survey. Changes in the Annual Social and Economic Supplement were less substantial and mainly reflected the shift to computer-assisted interviews.
  • 2008: Added the six ACS disability questions. See Disability and Disability Types - ACS.

A dataset (sometimes spelled data set) is a collection of observations or data points that are typically organized in a structured way, such as in a table. For example, in the American Community Survey, the dataset is a collection of individual survey responses.

A dataset provides the raw material for statistical analysis and inference.

The Decennial Census is census of population and housing, taken by the US Census Bureau in years ending in 0 (zero), such as 2020 or 2030. Article I of the Constitution requires that a census be taken every 10 years for the purpose of reapportioning the US House of Representatives. See Congressional district.

The ACS definition of disability is based on six questions. A person is coded as having a disability if they or a proxy respondent answers affirmatively in one or more of six categories. The ACS began using the current set of disability-related questions in 2008, and it has continued to use them through the 2023 when this entry was written. The questions are:

  • Hearing Disability (asked of all ages): Is this person deaf or does he/she have serious difficulty hearing?
  • Visual Disability (asked of all ages): Is this person blind or does he/she have serious difficulty seeing even when wearing glasses?
  • Cognitive Disability (asked of persons age 5 or older): Because of a physical, mental, or emotional condition, does this person have serious difficulty concentrating, remembering, or making decisions?
  • Ambulatory Disability (asked of persons age 5 or older): Does this person have serious difficulty walking or climbing stairs? 
  • Self-Care Disability (asked of persons age 5 or older): Does this person have difficulty dressing or bathing? 
  • Independent Living Disability (asked of persons age 15 or older): Because of a physical, mental, or emotional condition, does this person have difficulty doing errands alone such as visiting a doctor's office or shopping?

Note: The Census Bureau refers to each of the individual types as “difficulty,” while DisabilityStatistics.org uses the term “disability.”

More info: For more about the rationale and testing of the ACS 2008 disability questions, see the Census Bureau document Evaluation Report Covering Disability.

Based on Census 2000, disability includes any of the six disability types. It is a long-lasting physical, mental, or emotional condition that can make it difficult to do activities such as walking, climbing stairs, dressing, bathing, learning, or remembering (asked of persons ages 5 years old and older). It can also impede a person from going outside the home alone or working at a job or business (asked of persons ages 15 years old and older).

These are the six Census 2000 disability types:

  • Mental Disability: This is based on a two-part question: “Because of a physical, mental, or emotional condition lasting 6 months or more, does this person have any difficulty in doing any of the following activities: (a) learning, remembering, or concentrating …” (asked of persons ages 5 years old and older)
  • Physical Disability: This is based on a two part question: “Does this person have any of the following long-lasting conditions (b) a condition that substantially limits one or more basic physical activities, such as walking, climbing stairs, reaching, lifting, or carrying?”. (asked of persons ages 5 years old and older)
  • Self-Care Disability: This based on a two-part question: “Because of a physical, mental, or emotional condition lasting 6 months or more, does this person have any difficulty in doing any of the following activities: (b) dressing, bathing, or getting around inside the home...” (asked of persons ages 5 years old and older)
  • Sensory Disability: This is based on a two part question: “Does this person have any of the following long-lasting conditions (a) blindness, deafness, or a severe vision or hearing impairment...” (asked of persons ages 5 years old and older)
  • Go-Outside-the-Home Disability: This is based on a two-part question: “Because of a physical, mental, or emotional condition lasting 6 months or more, does this person have any difficulty in doing any of the following activities: (c) Going outside the home alone to shop or visit a doctor’s office?” (asked of persons 15 years old or older)
  • Employment Disability: This is based on a two-part question: “Because of a physical, mental, or emotional condition lasting 6 months or more, does this person have any difficulty in doing any of the following activities: (d.) Working at a job or business?” (asked of persons 15 years old or older)

The ACS defines earnings as wages, salary, commissions, bonuses, or tips from all jobs. This includes self-employment income (net income after business expenses) from own nonfarm businesses or farm businesses, including proprietorships and partnerships.

On DisabilityStatistics.org, our definitions for education are based on responses to the ACS question: “What is the highest degree or level of school you have COMPLETED? If currently enrolled, mark the previous grade or highest degree received.”

  • Less than a High School Education: This includes the ACS options “No schooling completed” through “12th grade NO DIPOLOMA”.
  • A High School Diploma or Equivalent: This includes the ACS options “Regular high school diploma” and “GED or alternative credential.”
  • Some College/Associate Degree: This includes the ACS options “Some college credit, but less than 1 year of college credit”; 1 or more years of college credit, no degree;” and “Associate’s degree (for example: AA, AS).”
  • A BA Degree or Higher: This includes the ACS options “Bachelor’s degree (for example: BA, BS)”; “Master’s degree (for example: MA, MS, MEng, MEd, MSW, MBA)”; “Professional degree beyond a bachelor’s degree (for example: MD, DDS, DVM, LLB, JD)”; and “Doctorate degree (for example: PhD, EdD).”

Note: In 2008, changes were made to some response categories and the layout of this question.

This Class of Worker (COW) category includes people who worked for wages, salary, commission, tips, pay-in-kind, or piece rates for a private, for-profit employer but are not self-employed in their own incorporated business.

For the ACS, a person is considered employed if they are either:

  • “at work”: Those who did any work at all during the reference week as a paid employee (worked in his or her own business or profession, worked on his or her own farm, or worked 15 or more hours as an unpaid worker on a family farm or business)
  • “with a job but not at work”: Had a job but temporarily did not work at that job during the reference week due to illness, bad weather, industrial dispute, vacation, or other personal reasons

Note: The reference week is the week preceding the date the questionnaire was completed.

More info: How does the ACS define an employed person?

The CPS employment rate is estimated each March, which is when the CPS Annual Social and Economic Supplement and its work-limitation question are asked. Also known as the employment-to-population ratio, the employment rate is the percentage of the population that is employed. Persons who can respond that they are employed are those 16 years and over in the civilian, non-institutional population who, during the full week prior to their survey:

  1. Did any work at all (at least 1 hour) as paid employees, worked in their own business, profession, or on their own farm, or worked 15 hours or more as unpaid workers in an enterprise operated by a member of the family, and 
  2. All those who were not working but who had jobs or businesses from which they were temporarily absent because of vacation, illness, bad weather, childcare problems, maternity or paternity leave, labor-management dispute, job training, or other family or personal reasons, whether or not they were paid for the time off or were seeking other jobs.

Each employed person is counted only once, even if they hold more than one job. Excluded are persons whose only activity consisted of work around their own house (painting, repairing, or own home housework) or volunteer work for religious, charitable, and other organizations. The total population (the denominator of the employment rate) consists of persons who are employed, persons who are unemployed, and persons not in the labor force.

Note: The employment rate is not 100 minus the unemployment rate.

This Class of Worker (COW) category includes people who were employees of any federal governmental unit. This includes government workers not working in public administration. For example, people working in the National Park Service are classified as federal government workers.

For the ACS, a person is considered employed full-time/full-year if they worked 35 hours or more per week (full-time) and 50 or more weeks per year (full-year).

Notes:

  • The reference period is the 12 months preceding the date the questionnaire was completed.
  • This does not signify whether a person is eligible for fringe benefits.
  • In 2008, the ACS question and response categories regarding weeks worked per year were changed.

For the CPS, the Census Bureau considers a person to have full-time/full-year employment if they reported having worked 50 weeks or more and an average of 35 hours or more per week in the calendar year. This definition does not indicate whether the person is eligible for health insurance benefits.

This Class of Worker (COW) category includes people who were employees of any local, state, or federal governmental unit. This includes government workers not working in public administration. For example, people who work in a public elementary school or for the state police are classified as government workers.

A GQ is a place where people live or stay that is normally owned or managed by an entity or organization providing housing and/or services for residents. 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. See Institutional GQs and Non-institutional GQs.

Health Insurance Coverage in the ACS is based on the following question:

Is this person CURRENTLY covered by any of the following types of health insurance or health coverage plans? Mark “Yes” or “No” for EACH type of coverage in items a–h.

  1. Insurance through a current or former employer or union (of this person or another family member)
  2. Insurance purchased directly from an insurance company (by this person or another family member)
  3. Medicare, for people 65 and older, or people with certain disabilities
  4. Medicaid, Medical Assistance, or any kind of government-assistance plan for those with low incomes or a disability
  5. TRICARE or other military health care
  6. VA (including those who have ever used or enrolled for VA health care)
  7. Indian Health Service
  8. Any other type of health insurance or health coverage plan – Specify (Note: “Other type” were recoded into one of the categories a–g by the Census Bureau)

For the ACS, Hearing Disability is based on the question (asked of all ages): Is this person deaf or does he/she have serious difficulty hearing?

For the ACS, people of Hispanic or Latino origin are those who classify themselves in a specific Hispanic or Latino category in response to the question, “Is this person Spanish/Hispanic/Latino?”

Specifically, those of Hispanic or Latino origin are those who are Cuban; Mexican, Mexican American, Chicano; Puerto Rican; or other Spanish/Hispanic/Latino. Origin may be the heritage, nationality group, lineage, or country of birth of the person or the person’s parents or ancestors before their arrival in the United States. People who identify their origin as Spanish, Hispanic, or Latino may be of any race.

For the ACS, Household Income is the total income of a household, including all the following:

  • Wages, salary, commissions, bonuses, or tips from all jobs
  • Self-employment income (net income after business expenses) from own non-farm or farm businesses, including proprietorships and partnerships
  • Interest, dividends, net rental income, royalty income, or income from real estates and trusts
  • Social Security or Railroad Retirement
  • Supplemental Security Income
  • Any public assistance or welfare payments from the state or local welfare office
  • Retirement, survivor, or disability pensions
  • Any other regularly received income (e.g., Veterans’ payments, unemployment compensation, child support, or alimony)

Note: Both the Census Bureau and DisabilityStatistics.org calculate median household income with the household as the unit of analysis, using household weights without adjusting for household size.

For the ACS, Independent Living Disability is based on the question (asked of persons age 15 or older): Because of a physical, mental, or emotional condition, does this person have difficulty doing errands alone such as visiting a doctor’s office or shopping?

Industry is a Work Characteristic collected by the ACS. It is the kind of business of the person’s employer.

Note: Industry refers to the person’s job during the previous week of when they were surveyed. For people who worked two or more jobs, it refers to the job where they worked the greatest number of hours.

More info: See Frequently Asked Questions about Industry and Occupation, from the US Census Bureau.

For the ACS, institutional group quarters includes facilities for people under formally authorized, supervised care or custody at the time of enumeration. These people are generally restricted to the institution, under the care or supervision of trained staff, and classified as “patients” or “inmates.”

Examples include correctional, nursing, and in-patient hospice facilities, psychiatric hospitals, juvenile group homes, and residential treatment centers.

This Class of Worker (COW) category includes people who were employees of any local governmental unit. This includes government workers not working in public administration. For example, people who work in a public elementary school or for a city-owned bus line are classified as local government workers.

The margin of error (MOE) is a measure of the degree of sampling variability. Survey data, such as from the ACS or CPS, are based on a sample, and estimates derived from this data are subject to sampling variability. In a random sample, the degree of sampling variation is determined by the underlying variability of the estimate (for example, income) and the size of the sample (i.e., the number of survey participants used to calculate the statistic). The smaller the margin of error, the lower the sampling variability and the more “precise” the estimate.

A margin of error is also the difference between an estimate and its upper or lower confidence bounds. An upper confidence bound is calculated by adding the MOE to the estimate, and a lower confidence bound is calculated by subtracting the MOE from the estimate. When confidence bounds are calculated using a 90% MOE, there is a 90% certainty that the actual value lies somewhere between the upper and lower confidence bounds.

The median is the middle value in a group of numbers. It separates the lower half from the higher half. For example, in the following group, 3 is the median: 1, 2, 3, 5, 11.

A median is often used instead of an average to characterize the incomes of people in a population. Median income is the amount that divides the income distribution into two equal groups, half having incomes above the median, half having incomes below the median. We use median income instead of average income because average income can be influence by extreme income amounts of only a few people in the population.

The federal Office of Management and Budget defines geographic entities for use by federal statistical agencies. These entities, called Metropolitan Statistical Areas (MSAs), are based on the concept of a core area with a large population nucleus, plus adjacent communities having a high degree of economic and social integration with that core.

Qualification as an MSA requires the presence of a city with 50,000 or more inhabitants, or the presence of an Urbanized Area (UA) and a total population of at least 100,000 (75,000 in New England). The county or counties containing the largest city and surrounding densely settled territory are central counties of the MSA. Additional outlying counties qualify to be included in the MSA by meeting certain other criteria of metropolitan character, such as a specified minimum population density or percentage of the population that is urban. MSAs in New England are defined in terms of minor civil divisions, following rules concerning commuting and population density.

When writing about samples, a shortcut for indicating how many people or items were included in a sample is to write n=number of samples. For example, if 870 people filled out a survey questionnaire, you could describe the sample size by writing n=870.

For the ACS, non-institutional group quarters includes group quarters that are not classified as institutional, such as college/university housing, group homes intended for adults, residential treatment facilities for adults, workers’ group living quarters, Job Corps centers, and religious group quarters.

For the ACS, a person is considered not in the labor force if they are not currently employed and not actively looking for work in the previous 4 weeks.

DisabilityStatistics.org defines a person as not working but actively looking for work if they report that during the past 4 weeks they were not employed but were actively looking for work.

Occupation is a Work Characteristic collected by the ACS. It is the kind of work a person does at their job.

Note: Occupation refers to the person’s job during the previous week of when they were surveyed. For people who worked two or more jobs, it refers to the job where they worked the greatest number of hours.

More info: Frequently Asked Questions about Industry and Occupation, from the US Census Bureau.

The poverty measure is computed by the Census Bureau based on standards defined in Directive 14 from the Office of Management and Budget. These standards use poverty thresholds created in 1982 and index these thresholds to current dollars using poverty factors based on the Consumer Price Index. They use the family as the income sharing unit, and family income is the sum of the total income from each family member living in the household.

The poverty threshold depends on the size of the family, age of the householder, and number of related children under age 18.

Prevalence is a way to measure how common something is at a specific time. On this website, prevalence refers to the percentage or number of persons reporting that they have a disability.

The disability prevalence rate is calculated by dividing the number of people reporting a disability by the total number of people in the population. This number is then multiplied by 100 to result in a percentage.

This Class of Worker (COW) category includes people who worked for wages, salary, commission, tips, pay-in-kind, or piece rates for a private, for-profit employer. This category includes two sub-categories: Employee of private company workers and Self-employed in own incorporated business workers.

This Class of Worker (COW) category includes people who work for a private not-for-profit, tax-exempt, or charitable organization.

For the ACS, Self-Care Disability is based on the question (asked of persons age 5 or older): Does this person have difficulty dressing or bathing?

This Class of Worker (COW) category includes people who are paid employees of their own incorporated businesses.

This Class of Worker (COW) category includes people who worked for profit or fees in their own unincorporated business, profession, or trade, or who operated a farm.

This Class of Worker (COW) category includes people who were employees of any state governmental unit. This includes government workers not working in public administration. For example, people who work in a state park or for the state police are classified as state government workers.

A person is defined as receiving Supplemental Security Income (SSI) payments if they report receiving SSI income in the 12 months prior to the survey. The SSI program is run by the US Social Security Administration, and it provides monthly payments to people who have limited income and savings, and who meet the Social Security Administration’s definition of disability.

This is a Class of Worker (COW) category includes people who worked without pay in a business or on a farm operated by a relative for 15 hours or more per week.

A Veteran Service-Connected Disability is a disease or injury determined to have occurred in or to have been aggravated by military service. The US Department of Veterans Affairs evaluates a disability according to the VA Schedule for Rating Disabilities in Title 38, C.F.R., Part 4. Extent of disability is expressed as a percentage from 0% (for conditions that exist but are not disabling to a compensable degree) to 100%, in increments of 10%.

This information is determined by the following two-part question on the ACS: 

  1. Do you have a VA service-connected disability rating? Responses include: “Yes (such as 0%, 10%, 20%, ... , 100%)” and “No.”
  2. What is your service-connected disability rating? Responses included: “0 percent,” “10 or 20 percent,” “30 or 40 percent,” “50 or 60 percent,” and “70 percent or higher.”

For the ACS, Visual Disability is based on the question (asked of all ages): Is this person blind or does he/she have serious difficulty seeing even when wearing glasses?

The ACS collects three types of information about an individual’s work:

Note: Work Characteristics refer to the person’s job during the previous week from when they were surveyed. For a person who worked two or more jobs, Work Characteristics refer to the job where they worked the greatest number of hours.

More info: Frequently Asked Questions about Industry and Occupation, from the US Census Bureau. test