Glossary

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.

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 glossary text 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 ages 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 ages 5 or older): 
    Does this person have serious difficulty walking or climbing stairs? 
  • Self-Care Disability (asked of persons ages 5 or older):
    Does this person have difficulty dressing or bathing? 
  • Independent Living Disability (asked of persons ages 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.”

For more information regarding the rationale and testing of the ACS 2008 disability questions, see the Census Bureau document Evaluation Report Covering Disability.

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

In the United States, each state is divided into congressional districts (CDs). Registered voters within each districts elect a representative to the US Congress. 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.

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.

Decennial describes an event that recurs every 10 years. For example, the US Decennial Census takes place every 10 years.

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.

The American Community Survey defines earnings as wages, salary, commissions, bonuses, or tips from all jobs including 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 American Community Survey 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 is a Class of Worker (COW) category that 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 own incorporated business.

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.

On this website, estimate has a specific meaning. An estimate is a number or percentage that comes from a statistical information. A statistic describes only the actual data from a survey or study, such as the number of people in that survey who reported a mobility disability. An estimate uses the statistical data to infer something about the overall population, such as the number of people in the United States who have a mobility disability.

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

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 question and response categories regarding weeks worked per year were changed.

This is a Class of Worker (COW) category that includes people who were employees of any local, state, or federal governmental unit. These categories also include 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.

Is based on the following American Community Survey 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)

The Census Bureau defines Household Income as 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.

Industry is a Work Characteristic collected by the American Community Survey. 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.

For more information, see Frequently Asked Questions about Industry and Occupation, from the US Census Bureau.

This is a Class of Worker (COW) category that includes people who were employees of any local governmental unit. These categories also include government workers not working in public administration. For example, people who work in a public elementary school or 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 what is being estimated (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.

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.

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 who is not working but actively looking for work as a person reporting not being employed but having been actively looking for work during the last 4 weeks.

Occupation is a Work Characteristic collected by the American Community Survey. 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.

For more information, see 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 is a Class of Worker (COW) category that 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 is a Class of Worker (COW) category that includes people who work for a private not-for-profit, tax-exempt, or charitable organization.

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

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

This is a Class of Worker (COW) category that includes people who were employees of any state governmental unit. These categories also include 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 that 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%.

The ACS determines this information with a two-part question: 

  1. Do you have a VA service-connected disability rating? “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.”

The American Community Survey 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.

For more information, see Frequently Asked Questions about Industry and Occupation, from the US Census Bureau.