The role of controlled experiments in understanding variation in flake production
Understanding chipped-stone technology essentially comes down to understanding how a single flake is made. Even though a knapper may remove many flakes to prepare a core or shape a piece, thin it, or modify its edges, each and every one of these removals requires a certain degree of control so that particular effects are achieved. While there is currently an emphasis in lithic analysis on reconstructing the totality of various reduction sequences (e.g., see Olszewski, chapter 4, this volume; Rollefson, chapter 10, this volume), we still have much to learn about how individual flakes are formed. In order to quantify the various mechanical aspects of flake production, a number of researchers have designed experiments under highly controlled conditions, often using shaped cores and mechanical strikers. These types of experiments allow control over several aspects of flaking, from the angle and force of the blow and type of hammer used to various core surface and platform morphologies. In this way, it is possible to study in a very detailed fashion the effects of particular independent variables on flake morphology. Such experiments are called "controlled experiments" because their goal is to control as many as possible of the variables involved with knapping in order to isolate the effects of a single variable. Because of the design of these kinds of experiments, such controls are much tighter than is generally possible with replicative flint-knapping experiments, and the results are clearly more amenable to quantification. On the other hand, the downside of many controlled experiments is that the processes and products do not always accurately simulate archaeological ones. This artificial nature inherent to many controlled experiments has often made it difficult to apply the results directly to archaeological materials.