This survey is part of Centerdata's Telepanel project. Telepanel consists of approx. 2000 households, surveyed weekly. Besides the Centerdatabase offers opportunities to compose tailor-made datasets. Knowledge and opinions about environmental organisations and organisations for the protection of nature / membership of these kind of organisations Background Variables: Age, year of birth / Sex Ownership of house Nr. of children living with family/household / Position in family/household / Size of family/household / Other: presence of partner in family/household Respondent: occupational status Respondent: gross income / Respondent: net income / Total family/household: gross income / Total family/ household: net income Respondent: highest grade attained / Respondent: highest type attended Other: constructed variable ( social economic class ) according to GFK * Dongen.