For example, during a conversation with a person without higher education, the interviewer may voluntarily replace the question ‘What kind of education your children are? ” question ‘Perhaps your children are not taught at the institute? “. This is an obvious mistake of asking the question. In most cases, a personal interview for the respondent is an entirely new experience, as a result of the interviewer becomes a major source of tips on how to behave. The interviewer should give the impression of a man who can understand his point of view party, and do so without rejecting his opinion. Accordingly, the failure of interviewers to be ‘on same wavelength’ with respondent provokes an error of imposing impression.

Error intervention, fraud, and fraud – the most acute problem of marketing research. The problem of fraud and deception on the part of interviewers is due to several reasons, including modest salaries, lack of control and low cultural and disciplinary level. Fraud can be very serious when fabricated will be all the interview entirely, or focus on particular questions, the answers are not received in the course of the conversation with the respondent. Since this leads to serious errors, many research companies are testing up to 50% of the results interview. This process involves repeated, usually a phone survey of a number of participants study. Non-response error is a significant problem, because people who refuse to participate in the study are likely to be significantly different from those who went on co-operation.