Needs and Directions of Improving Quality of Opinion Polls

In the paper some ways of improving quality of sample surveys, including opinion polls and pre-election polls are discussed.The author concentrates on three main issues:(1) - discrepancies between the structures of surveyed respondents and those who actually take part in elections; (2) - refusals by some respondents to co-operate in the survey (non-response); (3) - late changes of election preferences by some people (late swing). The author presents how some foreign pollsters cope with those issues and what lessons can be learnt from their experience.