Categories

Abstract

The batches of numbers that we have discussed in Chapters 1–5 have all consisted of a set of measurements of some kind. There is a fundamentally different kind of batch that we must discuss before continuing with the second section of this book. This other kind of batch results from observations of characteristics that are not measured exactly, but instead are grouped into different categories. Archaeologists are quite accustomed to the notion of categorizing things. We usually discuss it under the heading of typology, and the definition of typologies (or sets of categories) for artifacts is widely recognized as a fundamental initial step in description and analysis. Much has been written about the “correct” way to define pottery types in particular. Our concern here is not how to define categories, but rather what to do with the result once we have defined them and counted up how many things there are in each one. When we classify the ceramics from a site as Fidencio Coarse, Atoyac Yellow-White, and Socorro Fine Gray, we are dealing in categories. When we count the number of flakes, blades, bifaces, or debitage from a site, we are also dealing in categories. When we add up the number of cave sites and open sites in a region, we are once again dealing in categories. When we divide the sites in a region into large sites, medium-sized sites, and small sites, we are still once more dealing in categories. Data recorded in terms of such categories comprise batches just as do data recorded as true measurements (for example, in centimeters, grams, hectares, etc.).