The distinction between these three different types of expertise can be illustrated by imagining the experience of a social science researcher approaching a topic for the first time. It is easy to see that, whether the research project is to be about plumbing or physics, most researchers will start from a position of ‘no expertise’ in that area. As the research project proceeds and the social interactions between the researcher and the plumbers or physicists continue, the social researcher will become increasingly knowledgeable about that topic. For example, they will find that they can talk more interestingly about plumbing or physics and ask more pertinent questions about how it works. Eventually, the researcher may even get to the point where they can answer questions about plumbing or physics as though they were a plumber or physicist even though they can’t do plumbing or physics. It is this kind of expertise that Collins and Evans call interactional expertise.