Changes

When he served in the census bureaus from 1990 to 1992, Robert M. Groves favored sampling, rather than Actual Enumeration.  In 1999, Doc v. United States House of Representatives, 525 U.S. 316 (1999) ruled that sampling cannot be used in the count used for redistricting the House, but can be used in all other Census reports.   

When he served in the census bureaus from 1990 to 1992, Robert M. Groves favored sampling, rather than Actual Enumeration.  In 1999, Doc v. United States House of Representatives, 525 U.S. 316 (1999) ruled that sampling cannot be used in the count used for redistricting the House, but can be used in all other Census reports.   

"Hot deck" imputation is a way to solve the problem that people do not answer some questions and leave blanks or "missing values." The technique replaces the blank with an estimatebased on the actual response made by similar people to the same question.<ref> See John Stiller and Donald R. Dalzell, "Hot-deck Imputation with SAS Arrays and Macros for Large Surveys," (1997) [http://www2.sas.com/proceedings/sugi23/Stats/p246.pdf online]</ref> This adjustment technique has been approved by the Supreme Court<ref> Utah v. Evans, 536 U.S. 452 (2002)[http://caselaw.lp.findlaw.com/scripts/getcase.pl?navby=CASE&court=US&vol=536&page=452 online]</ref> and has no effect on the enumeration used to apportion the House, but does improve the accuracy of data on the characteristics of housing units in each locality.

"Hot deck" imputation is a way to solve the problem that people do not return their census questionnaires. The imputation technique replaces blanks with an estimate based on the actual response made by similar people.<ref> See John Stiller and Donald R. Dalzell, "Hot-deck Imputation with SAS Arrays and Macros for Large Surveys," (1997) [http://www2.sas.com/proceedings/sugi23/Stats/p246.pdf online]</ref> This adjustment technique has been approved by the Supreme Court<ref> Utah v. Evans, 536 U.S. 452 (2002)[http://caselaw.lp.findlaw.com/scripts/getcase.pl?navby=CASE&court=US&vol=536&page=452 online]</ref> even though iy can have an effect on the enumeration used to apportion the House. The Supreme Court has ruled it is not sampling, but a way to reduce errors in actual enumerations.  

==Undercount and Overcount==

==Undercount and Overcount==