Yes, It's pretty much accepted that there's an expectation bias in certain types of phone surveys. People often answer according to what they think would be an acceptable answer in relation to societal norms. So that bias especially pops up in matters of health, safety, race relations etc. and the interviewer doesn't get a true answer, they get what the respondent thinks they want to hear...Examples; *Question: Do you believe people should put working and making money before health & safety concerns? Odds are the respondent will almost answer health concerns, whether he/she actually believes that or not...* Are you a racist? Nearly everyone will answer no, whether they are or not........and that's one of the problems with national phone surveys that generally only interview 500 to 1,000 people. They're not all that accurate when it comes to certain types of questions.