ABSTRACT
The evidence available to an ethnographer is complete, for it can give information about the sum total of the activities of a human social group, whereas that available to a prehistorian reflects only a very small part of these activities. But the advantage which the prehistorian has over an ethnographer is that his evidence covers a much broader time-scale, involving in some cases many thousands of years. Thus, this prehistoric evidence can indicate, over a much longer period of time than is ever available to ethnographers, the gradual processes of technological, economic and even social change as a result of the diffusion, rejection, acceptance and adoption of innovations. It is unfortunate that at present the methods used by prehistorians are subtle enough to distinguish only the end rather than the beginning of these processes.
