Data Gathering
It is performed in 8 annual waves, employing face to face interviews in the home, on a representative sample of the adult population in Croatia (15+ years old), with sample size of N=1000 randomly chosen interviewees.
The data is gathered through face to face in-home interviews.
In-home interviews are conducted by well-trained interviewers, constant external assistants of GfK, and their work is constantly monitored by telephone control on 30% of sample.
GfK Omnibus is conducted on nationwide, representative, two-stage random sample of adults (15+).
The sample is stratified by regions (6 regions) and size of settlement (4 types of settlement), according to population data Census 2001.
Size of the total sample is 1000 respondents, in 103 sampling points in 76 towns.
At each sampling point the addresses are drawn at random, by random walk.
At each address, in each household, "the main” respondent is randomly selected out of all household members aged 15+ years, by the method of the (last) birthday date.
Omnibus sample can include 3 respondents in each household:
- "the main” respondent, randomly selected, male and female, aged 15+ years(N=1000)
- housewife, person that takes care of the household (N = 650)
- head of household, usually oldest male person in the household(N = 650).
One group of questions is answered only by one respondent in household.
Standard demographics included in the questionnaire are: region, settlement size, age, gender, marital status, education, working status, occupation, personal income, position in the household, number of household members, number of children in the household, household monthly net income, income resources, type of dwelling and self-estimation of social class.
