Data collection modes

In order to optimise the ratio between the quality of data collected through statistical surveys and their collection and processing costs, assiduous attention is devoted to the improvement of statistical data collection and processing methods, preparation and testing of statistical questionnaires.

Statistical population survey data are obtained from two sources – respondents (individuals) and State registers. The data stored in State registers are transferred to electronic statistical questionnaires or combined with the data collected through interviews when producing statistical information.

State Data Agency uses the following data collection modes:

• Face-to-face interview. This method is used when the respondent is interviewed for the first time, when only the address of his/her place of residence is known, while all other contact details are unknown. Interviews are usually conducted at respondent's home. During face-to-face interviews, a larger number of and more diverse questions are asked. The interview itself is longer than other types of interview. Face-to-face interview is an expensive and long process. Another negative aspect of face-to-face interviews is the fact that respondents are usually rather reluctant to let a strange person in.

• Internet interview. It is the most convenient type of interview for respondents. State Data Agency, striving to reduce the statistical response burden for respondents, widely uses data stored in State registers. That is why e-questionnaires are partially prefilled with data, i.e. data available in registers are transferred to e-questionnaires. An official letter to a respondent contains electronic survey system login codes. The respondent may log-in to and fill-in an e-questionnaire whenever convenient to her/him. S/he may terminate the filling-in process before s/he has answered all the questions but save the data entered; later, having logged in to the system again, s/he may finish the filling-in of the e-questionnaire. Those respondents who have no possibility or do not want to fill-in e-questionnaires themselves are questioned by interviewers, who visit respondents at home and fill-in questionnaires together with them.

• Phone interview. This interview mode is used when the respondent is interviewed for the second or subsequent time or her/his contact details are available, and the statistical questionnaire is not complicated. An interviewer of State Data Agency contacts the respondent by phone. The respondent may choose the interview time that is convenient to her/him.

• State registers. State registers store data which are used not only for administrative but also for statistical purposes, which reduces the statistical response burden for respondents. Data obtained from State registers are combined with the data collected through interviews.