Journal of Archaeological Science 1981, 8, 283-296 New Experimental Evidence on the Relation Between Percussion Flaking and Flake Variation Harold L. Dibble0 and John C. Whittakerb Controlled experiments in percussion flaking allowed for objective analysis of relationships betweenvariablesof flake production and those variableswhich are attributes of the final result. The independent variables, those controlled by the flintknapper in the production of stone tools, include force and angle of blow, platform thickness and exterior platform angle. The dependent variablesare those attributes of the flakeswhich are often usedin current lithic analyses and include interior platform angle, length, thickness and flake termination. The results clearly show that exterior platform angle is highly significant for understanding many aspectsof flake production. These and other relationships between the independent and dependent variablesare alsodiscussed. Keywords: LITHIC PRODUCTION, FLAKE MECHANICS, FLAKE ATTRIBUTES, EXPERIMENTAL FLINTKNAPPING, CONTROLLED EXPERIMENT, FLINTKNAPPING, EXPERIMENTAL ARCHAEOLOGY. Introduction The production of flaked stone tools involves the controlled breaking of materials which fracture conchoidally. A good knapper has a great deal of control over his material, and can produce very consistent results. In the days of gun-flint production at Brandon, England, a skilful “flake? could make around 10,000 blades in a day, or, in knapping these to form finished products, could produce between 3000 and 4000 extremely regular gun-flints (Skertchly, 1879). In making these or other artifacts of stone, the knapper directs his actions and manipulates certain variables of the material itself, thereby controlling the reactions and form of the piece he is working. The regularity of the results suggests that the degree of control is high, and therefore that certain variables are extremely regular and interrelated. It is the purpose of this study to isolate several of these variables and attempt to determine the nature and extent of the relationships between them. As knappers, the authors approached this problem from the point of view of the knapper who acts consciously to produce a desired end-product. However, the number of variables which must be controlled in the manufacture of most artifacts makes it impossible to do this kind of study solely on the basis of replicative experiments, in which “Arizona State Museum, University of Arizona, Tucson, Arizona 85721, U.S.A. bDepartment of Anthropology, University of Arizona, Tucson, Arizona 85721, U.S.A. 283 0305-4403/81/030283+14 $02.00/O (Q 1981 Academic Press Inc. (London) Limited