In
statistics
Statistics (from German language, German: ''wikt:Statistik#German, Statistik'', "description of a State (polity), state, a country") is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of ...
, non-sampling error is a catch-all term for the deviations of estimates from their true values that are not a function of the sample chosen, including various
systematic error
Observational error (or measurement error) is the difference between a measured value of a quantity and its true value.Dodge, Y. (2003) ''The Oxford Dictionary of Statistical Terms'', OUP. In statistics, an error is not necessarily a " mistak ...
s and
random error
Observational error (or measurement error) is the difference between a measured value of a quantity and its true value.Dodge, Y. (2003) ''The Oxford Dictionary of Statistical Terms'', OUP. In statistics, an error is not necessarily a " mistake ...
s that are not due to sampling.
[Dodge, Y. (2003) ''The Oxford Dictionary of Statistical Terms'', OUP. ] Non-sampling errors are much harder to quantify than
sampling errors.
[Fritz Scheuren (2005). "What is a Margin of Error?", Chapter 10, in]
What is a Survey?
", American Statistical Association, Washington, D.C. Accessed 2008-01-08.
Non-sampling errors in survey estimates can arise from:
[
* ]Coverage error
Coverage error is a type of non-sampling error that occurs when there is not a one-to-one correspondence between the target population and the sampling frame from which a sample is drawn. This can bias estimates calculated using survey data.Scheaf ...
s, such as failure to accurately represent all population units in the sample, or the inability to obtain information about all sample cases;
* Response errors by respondents due for example to definitional differences, misunderstandings, or deliberate misreporting;
* Mistakes in recording the data or coding it to standard classifications;
* Pseudo-opinion
The Metallic Metals Act was a fictional piece of legislation included in a 1947 American opinion survey conducted by Sam Gill and published in the March 14, 1947 issue of ''Tide'' magazine. When given four possible replies, 70% of respondents clai ...
s given by respondents when they have no opinion, but do not wish to say so
* Other errors of collection, nonresponse, processing, or imputation of values for missing or inconsistent data.[U.S. Census Bureau. March 2012. Introduction]
''Quarterly Financial Report for Manufacturing, Mining, Trade, and Selected Service Industries''. Fourth Quarter 2011.
p. xxi
An excellent discussion of issues pertaining to non-sampling error can be found in several sources such as Kalton (1983) and Salant and Dillman (1995),[Salant, Priscilla, and Don A. Dillman. "How to Conduct your own Survey: Leading professional give you proven techniques for getting reliable results." (1995).]
See also
* Errors and residuals in statistics
In statistics and optimization, errors and residuals are two closely related and easily confused measures of the deviation of an observed value of an element of a statistical sample from its "true value" (not necessarily observable). The err ...
* Sampling error
References
Survey methodology
Errors and residuals
Auditing terms
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