Observation in the clinic, testing in the laboratory, curve-tracing machines : we may think we know how physicians know. We don’t. That is because we have, until recently, ignored the primary medium in which medical knowledge occurs, namely, writing and its organisation and reorganisation on paper. Written patient records are almost as old as medicine itself and still central to its practice. Remarkably unexamined is how these have generated knowledge. The project aims to address a question (...)