TNS Gallup Channel Data Collection System
The TNS Gallup Channel (GallupChannel until 2008) is TNS Gallup's (Gallup Finland) computerised data collection system which has been in use since 1989. The same group of respondents responds to surveys on the website of TNS Gallup. Until 1999, PCs, and between 1999 to 2010, Internet terminals provided by Gallup Finland were used.
The panelists receive a personal email inviting them to participate in the survey and containing instructions on how to respond. The panelists can respond to the survey whenever suits them best and they are provided a telephone number and an email address they can contact in case they have questions.
The surveys can be completed weekly from Friday to Wednesday. The responses are quite evenly distributed between each day of the response period. Typically, the distribution of responses on the TNS Gallup Channel on different days is as follows:
|Time||% of responses|
|Monday||20 (1st reminder)|
|Wednesday||14 (2nd reminder)|
The sample is constantly controlled and updated. Panelists that have withdrawn from the sample are replaced with new panelists with similar profiles. About 35% of the respondent group changes annually.
Until 2011, when PCs/Internet terminals were used, members of a household were provided training in using the devices when they were delivered/installed. Using the Internet terminal and completing questionnaires did not require computer skills. In addition, the system provided a telephone advice service which the respondent households could contact during the response period. Households would respond to surveys every weekend. The response period began on Friday at 6 pm and ended on Tuesday at 8 am. When the terminal was opened at home, it was automatically connected via phone modem to Gallup Finland's mainframe, and a new questionnaire became available for completion. The questionnaires were addressed to particular members of the household according to the target group of each questionnaire. When all the questionnaires addressed to the household were answered, the last respondent contacted the mainframe, and the completed questionnaires were transferred to its memory.
A nation-wide sample is used in the datasets archived by the Finnish Social Science Data Archive. The sample is selected using multistage stratified sampling. It is representative of people living in Finland aged 15 or over, excluding only the population of the Swedish-speaking Åland Islands.