Definitions
Article 2
For the purposes of this Regulation, the following definitions shall apply: (1) ‘proxy interview’ means an interview with someone other than the person from whom information is being sought following specific rules set by each survey specifying in which cases proxy interviews can be accepted; (2) ‘non-response’ means the failure of a survey to collect data for all data items in the survey questionnaire or from all of the population units designated for data collection, or both, specifically: (a) ‘unit non-response’ is a type of non-response occurring when no data are collected about a population unit designated for data collection; (b) ‘item non-response’ is a type of non-response occurring when no data are collected about a survey variable in relation to a designated population unit; (3) ‘sampling error’ means part of the difference between a population value and an estimate of that value derived from a random sample, arising from the fact that only a subset of the population is enumerated; (4) ‘non-sampling error’ means error in survey estimates that is not attributable to sampling fluctuations; (5) ‘substitution’ with regards to respondents means the replacement of a unit that was originally sampled by another unit, including an inter- or intra-household replacement; (6) ‘eligible units’ means the set of population units selected from the sample frame that are part of the target population; (7) ‘ineligible units’ means units in the sample that are not part of the target population; (8) ‘net sample’, also referred to as ‘achieved sample’, means the set of population units (including substitution units) selected from the sampling frame, from which enough information has been obtained to include the unit in the survey estimations; (9) ‘gross sample’, also referred to as ‘initial sample’, means the set of population units initially selected from the sampling frame. The gross sample comprises the eligible units (the net sample and the non-response units) as well as the ineligible units; (10) ‘imputation’ means a procedure for entering a value for a specific data item where no response is available.