Materials and Methods

To determine the origin of archaeological spindle graphs, and to track the frequency of use of each of several types of graph used to diagram culture change, a sample of North American archaeological literature was examined. Numerous series of monographs and volumes of journals in both the archaeological and the paleontological literature were inspected. If a graph of biological (paleontological) or cultural (archaeological) change was included in a publication, that piece of literature was recorded along with the type of graph included. To record such data, a classification of graph types was developed based on categories of statistical graphs (e.g., bar graph, line graph, pie graph, time range, spatio-temporal rectangle). More than 900 pieces of literature on North American archaeology published between ~1880 and ~1960 were inspected, and more than 450 pieces of literature on paleontology were inspected. Because different graph types are constructed under different guidelines, they require an understanding of graph grammar—the rules for constructing, deciphering, and interpreting graphs.