The Natural History of an Interview (NHI) began in 1955 at the Center for Advanced Study in the Behavioral Sciences. NHI was an applied project, as well as multi-, inter-, and transdisciplinary, involving a core group of well-established researchers, all of which were central to its results and influence. The result was a new framework for thinking about communication in face-to-face interaction, including the development of new tools, and a set of principles for analysis. The natural history method focuses on fine-grained observation and analysis of observable behavior during social interaction. Originally involving half a dozen researchers for an academic year, then several dozen scholars over a decade, the assumptions and methods of NHI contributed significantly to the assumptions and techniques used to study interaction today.