|Data Source:||U.S. Census Bureau|
Universe: Occupied housing units
|Summary File 3 Technical Documentation -> Appendix C. Data Collection and Processing Procedures -> Glossary -> Imputation|
When information is missing or inconsistent, the Census Bureau uses a method called imputation to assign values. Imputation relies on the statistical principle of "homogeneity," or the tendency of households within a small geographic area to be similar in most characteristics. For example, the value of "rented" is likely to be imputed for a housing unit not reporting on owner/renter status in a neighborhood with multiunits or apartments where other respondents reported "rented" on the census questionnaire. In past censuses, when the occupancy status or the number of residents was not known for a housing unit, this information was imputed.
Internet Questionnaire Assistance (IQA)
An operation which allows respondents to use the Census Bureau's Internet site to (1) ask questions and receive answers about the census form, job opportunities, or the purpose of the census and (2) provide responses to the short form.
Interpolation frequently is used in calculating medians or quartiles based on interval data and in approximating standard errors from tables. Linear interpolation is used to estimate values of a function between two known values. Pareto interpolation is an alternative to linear interpolation. In Pareto interpolation, the median is derived by interpolating between the logarithms of the upper and lower income limits of the median category. It is used by the Census Bureau in calculating median income within intervals wider than $2,500.
|Summary File 3 Technical Documentation -> Appendix B. Definitons of Subject Characteristics -> Housing Characteristics -> Telephone Service Available|
The data on telephones were obtained from answers to long-form questionnaire Item 41, which was asked on a sample basis at occupied housing units. Households with telephone service have a telephone in working order and are able to make and receive calls. Households whose service has been discontinued for nonpayment or other reasons are not counted as having telephone service available.
In Census 2000, the telephone question emphasizes the availability of service in the house, apartment, or mobile home. Data on telephone service are needed because an individual can own a telephone but have no service to make or receive calls. In 1980 and 1990, respondents were asked about the presence of a telephone in the housing unit. In 1960 and 1970, a unit was classified as having a telephone available if there was a telephone number on which the occupants of the unit could be reached. The telephone could have been in another unit, in a common hall, or outside the building.