Interviews can be good because they give qualitative data. This means it is more in depth than quantitative data such as results of questionnaires.
With interviews, a lot more information can be gained from the person because you can follow up questions with more questions based on what they say. You can't do this with a questionnaire.
A problem with interviews would be that you might get incorrect information based on the nature of a 1 to 1 interview as people may be reluctant to give out information if it's not going to be anonymous.
Just be aware that questionnaires can produce both quantitative and qualitative data, depending on the questions.
ReplyDeleteInterviewing can potentially also provide too much data- the researcher gets swamped. It can also take a long time, and be expensive.
-Fiona