Nonsampling errors

Conventional to split total survey error into sampling and non-sampling error. Non-sampling error includes all errors not attributable to incomplete enumeration.

In contrast to sampling errors, non-sampling errors often increase with sample size or complexity of sampling scheme. Non-sampling error likely to be at least as large as sampling error.

Types:

• coverage errors: frame errors, non-response
• measurement errors: question & format effects, respondent errors, interviewer effects
• processing errors