(a) Many people are willing and able to co-operate in a study when all they have to do is to talk,
(b) Another advantage of the interview is its greater flexibility. In an interview there is the possibility of repeating or rephrasing questions to make sure that they are understood.
(c) Its flexibility makes the interview a far superior technique for the exploration of areas, where there is little basis for knowing either what questions to ask or how to formulate them.
(d) The interviewing situation offers a better opportunity than the questionnaire to appraise the validity of reports.