During the Upper Paleolithic stone tools diversifies the suit so useful for every technical need. This means that human groups have to control the sources of raw materials, ie what places can supply flint mainly or quartzite. The analysis of the remains of flint carved in various French Paleolithic explained that within the group there are people who cut and prepare the necessary lithic material with great technical skill while others seem to be "apprentices", which explains the specialization of some people.
One of the procedures used to study the lithic technology is reassembly. Is to recover the chain of events that occurs since has the raw flint block to the manufacture of an object. This is achieved by recovering all flints upon studying the excavation and relative to each other, so to be "tracing" like a puzzle. Thus it is possible to know exactly how each of manufactured supplies found and therefore understand the technological knowledge of the human group being studied.