Jansen, H.A.M.

respondent alcohol alcohol consumption survey consumption questionnaire question interview study problem response drinking non-respondent non-response research difference expert review sample drink report process result frequency rotterdam non-response bias method review expert journal occasion drinker subject follow-up category month response rate estimate jansen pilot study behavior year consumption table response process comparison number habit self-completion rotterdam survey erasmus mc interviewer analysis netherland response problems population technique non-response follow-up study quality test-interview abstainer researcher scale beverage pilot fi xed utrecht survey pretesting attitude person utrecht topic instrument steps 1 information validity step 2 response categories erasmu group model observation