The number of key informant interviews (KIIs) needed for a study depends on the study's scope, diversity of participants, and the point at which data saturation is reached. For small, focused studies, 5–10 interviews may suffice, while moderate-scale studies typically require 10–20, and large-scale or diverse studies may need 20–30 or more. The aim is to capture diverse perspectives until no new insights emerge, balanced against time, budget, and logistical constraints.