ABSTRACT
This chapter considers the archaeological implications of three classes of models or surfaces generated by GIS: perception surfaces, effort or cost surfaces and time surfaces. It concludes with a review of the author's research on effort modified Thiessen polygons. Perception surfaces are images of how people view their world. The world that people live in, is not always delineated by the realities of physics. Distance is not always perceived as linear or indeed, ‘as a cost’ in calories or effort, but often in ‘roughness’ and difficulty. Correction factors for our modern map base may be derived directly by transforming known points using rubber-sheet geometry. More sophisticated approaches reclass raw slope values into bands, with low values changing little and higher values being distorted more. Perception must play a role in the calculation of realistic effort surfaces.
