This paper is drawn from a presentation, by John Morison, that was made to a plenary session of the 43rd BIALL Annual Study Conference in Belfast, Northern Ireland 2012. The presentation introduced the audience to a research study, recently funded by the Economic and Social Research Council, entitled “What Makes an ‘Important Case’? A Study of the Creation, Transmission and Validation of Legal Knowledge”, and being carried out with Professor Gordon Anthony. The presentation to BIALL also attempted to engage the audience of legal information specialists with the specifics of the project and enlist their help in understanding how an important aspect of legal practice actually works. This paper has the same objective, and, additionally, it reports on some of the initial findings of the research which aims to develop a comprehensive sociology of legal knowledge.