The sample size is 26,000 panellists, drawn from the total population using a stratified random sampling procedure. The population is divided into subpopulations (strata) and random samples are taken from each stratum. Stratification sorts the population into relatively homogeneous subgroups. The strata are mutually exclusive and comprise the entire population. Stratification is based on age, gender and licensing area. The number of panellists per stratum is proportional to the number of persons per stratum. For the purposes of extrapolation, however, over-sampling is required in the case of small populations (small geographical areas and Romansh speakers).

Recruitment is carried out by phone in (Swiss-)German, French, and Italian. In all three language areas of Switzerland, persons are recruited in all three national languages.