An In-Depth Interview (IDI) is a qualitative survey conducted over the phone or in-person, conducted by a trained interviewer. IDIs are open-ended, flowing conversations, with fewer participants. The interviewer goes in with an outline of discussion topics, but uses instinct and experience to guide the conversation to unearth critical insights.
- IDIs are 30 minutes to 1 ½ hours, depending on whether they are in-person or over the phone.
- Due to the flowing nature of how the interviews occur, we’re often able to dig deep into underlying causes of a problem, frustrations or issues.
- Because the interviews are conducted one-on-one, interviewers are able to “read between the lines.” Sometimes what’s NOT being said can offer as much, or more insight, as spoken answers.
- In an IDI, you usually get more of the “back story.”
Weakness & limitations
- Usually the sample sizes are small and are not projectable. (Just because 10 people see it that way doesn’t mean it holds true for the rest of the population.)
- It can be very hard, time-consuming and expensive to get people to sit down and talk with you for this long.