Archaeologists’ excavation practices vary significantly from country to country and site to site. But variation in the most fundamental, ‘common-sense’ excavation practices is ‘black-boxed’ - it is not discussed outside casual, informal contexts, and is treated as having no effect on higher-level interpretation. These practices can, however, be a source of conflict when archaeologists from different communities of practice work together. In this paper, I explore what variation in excavation methodology reveals about the nature of archaeological knowledge itself. By comparing methodologies and the organization of labour on British and Andean excavations, I argue that archaeologists in different communities of practice have divergent understandings of what the object of archaeological investigation is, and of how it can be known, and by whom. This results in contrasting understandings of the nature of material/archaeological objects, as well as contrasting conceptualizations of excavation as an ‘expert’ practice – one requiring skills, knowledge and bodily practices that are specific to trained archaeologists. Situating these concerns in historical and ethnographic context, this paper suggests that archaeological excavation is, in fact, a far more complex, nuanced and variable practice than the lack of attention paid to it implies.