COMMENTS ON THE USE OF CHIPPED STONE ARTEFACTS AS A MEASURE OF 'INTENSITY OF SITE USAGE' Peter Hiscock Recent work by Hughes (1977, 1980), Hughes and Djohadze (1980), and Hughes and Lampert (in press), has involved the calculation of indices of the 'intensity of site usage'. This has most commonly been done by plotting the number of implements per unit time throughout an archaeological sequence. The implications of this approach are best demonstrated in Hughes and am pert's model of south coast, NSW, prehistory, where they use such indices to measure population size and demographic change. While I believe that this work is a significant innovation in archaeological practices it has not yet controlled all the obvious variables involved in such statements. This paper discusses some of the assumptions which have been made when using data on chipped stone artefacts as a measure of the intensity of site usage. THE CONCEPT OF USAGE The 'site usage intensity' concept appears useful because it is so vague. 'Site usage' purports to be a comprehensive and consistent description of behaviour at any site and from a variety of measures: the amount of food remains, the amounts of chipped stone material, the amount of other organic residues etc. Each of these measures, however, records particular and different aspects of human behaviour at an archaeological site, and there- fore there need be no necessary agreement between any two as to the intensity of occupation at that site. For example, stone artefacts may be the result of certain procurement and knapping practices, whereas burnt bone may be the result of certain hunting, butchering, cooking and consuming practices. The question therefore arises, which objects should we choose as a measure of occupation intensity? Hughes (1977, 1980) has also hypothesised that 'occupation intensity' is a causal factor for deposit accumulation in sites on the south coast of NSW. In this model he again uses the number of implements per unit time as a measure of the intensity of occupation. As I have argued, however, different types of objects are the result of different types of behaviour. In Hughes' model the important causal relationship must be between each of the different types of debris (artefacts, bone, shell etc.) and the hypo- thesised mechanisms of sediment accumulation. The usefulness and accuracy of the 'intensity' concept can therefore only be judged by reference to what is