| Data Dictionary: | ACS 2009 (1-Year Estimates) |
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Survey: ACS 2009 (1-Year Estimates)
| Data Source: | U.S. Census Bureau |
Data set: American Community Survey 2009 (ACS09)
| Table: | B99185. Imputation of Ambulatory Difficulty for the Civilian Noninstitutionalized Population 5 Years and Over [3] |
Universe: Civilian noninstitutionalized population 5 years and Over
Table Details
| B99185. | Imputation of Ambulatory Difficulty for the Civilian Noninstitutionalized Population 5 Years and Over | ||||||||
| Universe: Civilian noninstitutionalized population 5 years and Over | |||||||||
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Relevant Documentation:
| Excerpt from: | Social Explorer; U.S. Census Bureau; American Community Survey 2009 Summary File: Technical Documentation. |
| ACS 2009-1yr Summary File: Technical Documentation -> Appendix A. Supplemental Documentation -> 2009 Subject Definitions -> Quality Measures -> Imputation Rates |
Missing data for a particular question or item is called item nonresponse. It occurs when a respondent fails to provide an answer to a required item. The ACS also considers invalid answers as item nonresponse. The Census Bureau uses imputation methods that either use rules to determine acceptable answers or use answers from similar housing units or people who provided the item information. One type of imputation, allocation, involves using statistical procedures, such as within-household or nearest neighbor matrices populated by donors, to impute for missing values.
This rate is calculated by adding together the weighted number of allocated items across a set of person characteristics, and dividing by the total weighted number of responses across the same set of characteristics.
This rate is calculated by adding together the weighted number of allocated items across a set of household and housing unit characteristics, and dividing by the total weighted number of responses across the same set of characteristics. These rates give an overall picture of the rate of item nonresponse for a geographic area.
| Excerpt from: | Social Explorer; U.S. Census Bureau; American Community Survey 2009 Summary File: Technical Documentation. |
| ACS 2009-1yr Summary File: Technical Documentation -> Appendix A. Supplemental Documentation -> 2009 Subject Definitions -> Population Variables -> Disability Status -> Ambulatory difficulty |
Ambulatory difficulty was derived from question 18b, which asked respondents if they had "serious difficulty walking or climbing stairs." Prior to 2008, the ACS asked if respondents had "a condition that substantially limits one or more basic physical activities such as walking, climbing stairs, reaching, lifting, or carrying." This measure was labeled "Physical difficulty" in ACS data products.
