Abstract concepts like “science” and “expert” are subject to varied academic and ordinary usage. When considered as names for worldly things, the words “science” and “expert” denote, respectively, a modern social institution and an agent (person or professional body) accredited with specialized knowledge. However, especially when used as adjectives, “scientific” and “expert” convey evaluations: they are used to claim or confer special status for activities, agents and agencies, statements, and evidences. The words “expert” and “science”/“scientific” are indexical expressions (Bar Hillel 1954; Garfinkel and Sacks 1970). When used under different circumstances, such expressions hold highly variable meanings and pragmatic implications. Moreover, “science”, “scientific”, “scientist” and “expert” are membership categories (Sacks 1972): in many formal and informal situations they are used tendentiously to claim or confer authority and credibility. In circumstances in which potential incumbents of such categories confront others who are in a position to accept, contest or deny membership, it becomes apparent that calling someone an “expert” or accepting a statement as “scientific” involves concrete (and sometime contestable) courses of action and interaction. The use of these words, and the performance of relevant actions to contextualize their use, is not simply a cognitive process of extending conceptual categories to cover new cases.
Formal definitions and rules of use (whether provided by dictionaries or legal statutes and precedents) can only take us a certain distance when we aim to appreciate the social significance of “science” and “expert”. For all their pleasures and advantages, scholarly analyses, and even reflective inventories of “ordinary” usage, are likely to miss the surprising moves generated in lively occasions of interaction. Armchair analysis - even when oriented to the “ordinary” - limits the imagination in some ways while it licenses it in others. Consequently, an examination of “actual” occasions of action and interactions (or their tape-recorded and transcribed proxies) can be useful, not - or not only - as a means of access to real worldly social activities, but as an “aid to a sluggish imagination” (Garfinkel 1967:38). A distinctive empirical, though not empiricist, orientation - akin to the phenomenological herald calling us “to the things themselves” - is implied in a painstaking examination of just how actions related to