Data collection methods

Statistics are compiled either based on data collected specifically for this purpose or by using other data, for example, collected by other authorities for administrative use. The Statistics Act requires that data are inquired from enterprises and citizens only if the necessary data do not already exist.

Thus, statistics are compiled from the answers provided by people. The data in administrative files are also often based on answers given on a form or a form filled out by an authority.

Who do we ask?
Data are collected from citizens and households, enterprises and corporations, such as associations, municipalities and the state.

How do we ask?
When planning a data collection it is always carefully assessed which data collection method is the best option in view of the objectives, quality and costs of the statistics or survey. The following is a list of the main data collection methods:

In a telephone interview, the questions must be such that they can be easily understood over the phone. The respondent can select a suitable and nice place and time for the interview. The method is most commonly used in collecting data concerning private persons and households. The interviews are short in duration. Only a few telephone interviews are conducted for enterprises.

Face-to-face interviews are usually carried out at the respondent's home or in some other place agreed in advance. Face-to-face interviews enable collection of data with various contents and they last longer than telephone interviews. This method is rarely used in data collections directed at enterprises.

In a postal inquiry, respondents are sent a paper form to be filled in. The method is used both in individual-based data collections and data collections from enterprises but growth in web-based data collections has decreased the use of this method. A special form of a postal inquiry is the diary method, where the respondent reports on the studied topic, for example, on time use or consumption.

Responding online is faster and cheaper than other data collection methods. It enables versatile ways of presenting questions to different respondent groups. Enterprises mainly respond with a web questionnaire. In some individual-based data collections responses can also be given online.

Web scraping is a data collection method by which the source code of a website is searched programmatically and the required data are extracted from it. 

Administrative data and registers are exhaustive in Finland. Their use as the basis for statistics does not increase the response burden for citizens and enterprises. The problem is that administrative data are sometimes difficult to convert into statistical use and the fact that changes in legislation and administrative practices can reduce the comparability of data. Administrative data can be combined with data derived from other collection methods.

Testing of questions and forms

The questions and forms are tested and assessed with a smaller group of people or enterprises than the actual data collection covers. Statistics Finland always contacts the persons or enterprises selected for the testing sample either by letter or email. The objective is to improve the quality of statistics and surveys, and to make answering as smooth as possible. More information: The Questionnaire Testing and Design Unit .