He is one of my favourites firts of all because he introduced the notions of the context to the archeology making the diference between the systemic context (when the objects are in use) and the archeological record (when the objetcs are deposited in the ground intencionally or not). The archeological record (or also named context) is the one thath archaeologyst studies.
This final idea is related with another big contribution (for my point of view) to the archaeology wich change the temporal limits of the discipline because he expressed that archaeology is the study of material culture in every time (not only the past!).
Another great contribution of Michael Shiffer is the study of the site formation process which says that the objets are afected by different cultural and natrual processes (for example the earthquakes).
