The in-depth interview is a method used primarily in qualitative research and is carried out upon individuals (one on one), rather than in a group discussion scenario. The interview takes part with a researcher and a respondent (the interviewee) the researcher normally uses a topic guide to guide the discussion and it usually lasts between 30 minutes to an hour. The interview helps the researcher to gain detailed and in depth information.
A one-on-one interview conducted over the phone or in-person. As with all qualitative research, IDIs are designed to uncover motivations behind certain behaviors, attitudes and perceptions — why one product is preferred instead of another or why customers aren’t buying a particular type of technology. IDIs may be used over focus groups for a variety of reasons. First, the cost is often lower (no facility rental, no travel expenses). Second, the sample population may be too geographically dispersed to conduct focus groups— it’s very difficult, for example, to find 6-8 cable operators in one city (see Focus Group). Finally, respondents may be competitors— VARs or Service Providers, for example, may be very reluctant to speak openly of their business strategies in front of competitors.