Estimate interview duration for research.
Interviewing time is dominated by what happens afterwards. Manual transcription runs at roughly four to six times real time, so twenty forty-five-minute interviews generate sixty hours of transcription against fifteen hours of interviewing. Adding scheduling overhead per participant gives a total that explains why qualitative studies are planned in months rather than weeks.
Component time
Interviewing minutes = interviews x length; transcription minutes = interviewing minutes x transcription ratio
Total effort
Total hours = (interviewing + scheduling overhead + transcription minutes) / 60
Substantially — machine transcription plus correction typically runs at one to two times real time rather than four to six. Accented speech, jargon and poor recordings narrow the advantage.
Saturation in homogeneous samples is often reached around twelve to twenty, but this depends heavily on the breadth of the research question and the diversity of participants.