Clinical interviewing is provocative and potentially fertile as a subject of study from the complementary perspectives of knowledge and interaction. Criticisms include that it is ecologically invalid; that clinical interaction is very likely to introduce interactional artifacts that obscure analysis of the subject's 'knowledge'; and even a skepticism concerning the validity of knowledge itself as stable and transportable to new contexts. As a topic for study, clinical interviewing is fertile because, although the methodology is mainly of interest to knowledge analysis (KA) researchers, clinical interviewing must have significant interactional properties that interaction analysis (IA) researchers are likely in the best position to understand. While the focus of clinical interviewing and subsequent analysis is knowledge, the means of the method transparently involves linguistically mediated interaction, which it behaves people to understand. On a broader front, some influential researchers of interaction particularly conversation analysts and ethnomethodologists sometimes at least give the appearance of denying the relevance of knowledge to understanding interaction.