The aim of market research should be to provide data to help solve marketing problems. This applies equally to industrial as well as consumer market research. Accepting this premise, the main task of market research, then, is to deal with commercial problems. In the consumer research field, to talk about interviewers in general can be dangerous. The interviewer who is perfectly capable of carrying out interviews for an omnibus survey is not necessarily able to conduct depth interviews. The ability of an interviewer is thus determined by the level of interview required.