Focus groups traditionally last 1 ½ to 3 hours and assemble 6 to 9 respondents together. Group discussions produce data and insights that would be less attainable without the interaction found only in a group dynamic. For instance, listening to the verbalized experiences from other respondents stimulates memories, ideas, and experiences. This is also known as the “group effect” where group members engage in “chaining” or “snow-balling”. Focus groups save time, providing qualitative information among 6 to 9 individuals in less than 3 hours.
Mini groups, which consist of 3 or 4 respondents, are less creative, but particularly adapted to “work sessions”, where respondents are asked to build a demonstration or a communication.
You can also mix IDIs and focus groups in the same central location to get the best of both worlds.