Using a entails a moderator guiding a group through a series of questions while other members of the research team monitor the interaction through a one-way mirror.

The answer is "focus group".

A focus group is a group discourse guided by a moderator. It is utilized to find out about sentiments on an assigned point, and to control future activity. For example a focus group of guardians of preschoolers meets to talk about child care needs. A focus group  generally comprises of few members.

it's the under parts of the car

an informal structure in a bureaucracy would be something like so-called "office politics". where there's a formal structure set up for the organization, but then an informal subculture as well that has a way of organizing the bureaucracy further. this can be positive because it sets up an added degree of organization, albeit informal, within the bureaucracy.