Interviews involve a social interaction between the interviewer and interviewee, whereas with written questionnaires the respondent usually answers the questions without the involvement of the researcher
An interview where the researcher allows the interviewee the opportunity to speak about those things they think are important, in contrast with a structured interview where the researcher decides in advance what questions are worth asking and limits interviewees to a fixed range of possible answers
Useful where the subject is one that we don't yet much about, because they are open-ended and exploratory
Can start out knowing nothing and, by asking questions, learn as we go along
Can be used as a starting point to develop initial ideas about a topic before going on to use more structured methods of investigation such as questionnaires
Unstructured interviews take a long time to conduct, often several hours each, which limits the number that can be carried out and means that the researcher will have a relatively small sample compared with the larger numbers who can be studied using structured interviews or questionnaires
Interviewers for unstructured interviews need to have a background in sociology so they can recognise when the interviewee has made a sociologically importantpoint and so they can probe further with an appropriate line of questioning
Interviewers for unstructured interviews need good interpersonal skills so they can establish the rapport that is essential if interviewees are to answer fully and honestly
The smaller numbers involved in unstructured interviews mean it is more likely that the sample interviewed will not be representative, making it harder to make validgeneralisations based on the findings
Unstructured interviews are not reliable because they are not standardised, with each interview being unique and the interviewer free to ask different questions in each case if they feel it is relevant to do so, making it virtually impossible for another researcher to replicate the interviews and check the findings or compare them with their own
Because unstructured interviews use mainly open-ended questions, the answers cannot be pre-coded, making it very difficult to count up and quantify the numbers of interviewees giving this or that answer, and in turn making unstructured interviews less useful for establishing cause-and-effect relationships and hypothesis testing that positivists prefer
Unstructured interviews are generally seen as producing valid data, but critics argue that the fact that they involve an interaction between interviewer and interviewee inevitably colours and distorts the information obtained
Structured interviews are favoured by positivists because they achieve the main positivist goals of reliability, generalisability and representativeness, while unstructured interviews are preferred by interpretivists because they achieve the main interpretivist goal of validity
Interviews, whether structured or unstructured, involve a social interaction between interviewer and interviewee, and the danger is that the interviewee may be responding not to the questions themselves but to the social situation in which they are asked
Interviewer bias can occur through leading questions, where the wording tells the interviewee how to answer, or through the interviewer's facial expressions, body language or tone of voice
Even the most relaxed of unstructured interviews is still an interview and not a normal conversation, and under these artificial conditions, it is sometimes doubtful whether truthful answers can be obtained
Inequalities between interviewer and interviewee, such as differences in status, gender, or ethnicity, may affect the interviewee's honesty or willingness to answer