In depth interview, a highly trained person goes on asking questions to encourage the respondent or respondents to talk freely about the subject matter in questions instead of administering a ready-made questionnaire. Interviewer asks the questions to draw out the emotions, feelings and opinions of the respondents and he develops the patterns of questions in such a way that he gets the maximum information on attitude.
Major strength of depth interview lies in the way it extends the interviewer's grasp of the consumer's attitude and the insight into them. Depth interview lasts for an hour to three hours. As long as depthinterviews do not degenerate into games of verbal wit between the interviewer and the subjects or into "free association" sessions they can yield useful information which the familiar questionnaire session is unlikely to uncover. This technique results in getting at the real and hidden reasons for the consumer actions than the usual announced answers.
Individual interviews have beenof special importance as they provide authentic feedback for developing new products, improving the existing products and developing new ways to talk to consumers through advertising. Individual depth interviews real true attitudes as there is no fear of social embrassment.
Group interviews is other variation under which eight to ten persons are brought together in a relaxing surroundings to discuss marketing or advertising and the subjects introduced by the trained group leader or the moderator.
Group leader knows that certain defined areas are to be covered in the course of one to three hours. Proceedings are recorded for future reference. Group sessions are better substitutes for face to face contact with the consumers. Draw backs of a group session is that the findings are not projectable.