Almost all qualitative research includes interviews in some form. Unlike observation, the technique of interviewing is to ask specific questions of the subjects of your study. It is interactive, in that you can follow up interesting responses, probe meaning, and observe verbal and non-verbal signals. There are different interview techniques, including:

¨ open-ended interviews, (unstructured) where the researcher has no specific questions, but is seeking insights - these can be useful when you are starting your study and want to identify areas for more in-depth research;

¨ focused interviews, (or semi-structured) where there are specific topics of enquiry, but no fixed questions. A set of questions has been prepared in advanced, but the researcher is free to modify them in the light of responses.

¨ structured interviews, where the researcher has a set of standard questions and responses, recorded on a schedule (effectively a questionnaire).

Whichever method you use, you must be clear at the outset what the objectives of the interview are in relation to your research. Prepare thoroughly in advance and remember to listen more than you speak, make your questions clear and easy to understand - avoid jargon - and try to eliminate clues, for example, through your tone of voice, which may lead your subject to respond in a particular way. Again, if you have not done this before, it is very helpful to have some practice prior to interviewing people as part of your research.

Conducting a large number of interviews is very time-consuming. You may, then, need to consider whether a postal survey would enable you to obtain basic information for your study more economically, and to reserve the use of interviews for exploring more complex aspects with a limited number of subjects. If the subjects of your case study are geographically dispersed, you may have to conduct telephone, rather than face-to-face, interviews. Sometimes, group interviews may be held, particularly if there is a clearly distinguishable body of people to study, but group dynamics and hierarchical differences can prevent some people from participating fully in a group setting, while it is difficult for the researcher to follow up individual responses properly.

One particular type of interview is the "critical incident", where a respondent is asked to concentrate on describing a recent significant event and how he/she reacted to it, as a means of obtaining data which may not be found through normal questioning.