As in any science, in the broadest sense of the term, archaeologists need to have meaningful categories for classifying and sorting the entities they study or searching for patterns in their observations (see Classification and Typology). We cannot even count things until we decide how to classify them. However, no particular system, or arrangement, for classifying phenomena or grouping similar phenomena is demonstrably ‘true’ or ‘natural’, and this sometimes leads to considerable debate among archaeologists about such things as whether the traces at a particular site belong to one or another culture or industry, whether a particular artifact is one or another kind of tool, and so on.
Such disagreements can arise because archaeologists classify or partition their observations on the basis of some selection of characteristics or attributes among an infinity of attributes that they conceivably could record. They also vary in their strategies and methods for making use of these attributes in the construction of conceptual categories. Consequently, the resulting systems of groups or categories can differ and, in some sense, are arbitrary. They are arbitrary not because all systems are equally useful or justifiable but because different archaeologists, with different goals, different methods, or different sets of entities to organize, will likely come up with quite different groups or categories that nonetheless serve their purposes. It is also quite unlikely that the categories that archaeologists use are very similar to, let alone identical to, the categories that prehistoric people would have used to describe their surroundings and material culture (their ‘ethnotaxonomy’).
However, archaeologists also want to provide reasonable justification for the categories and groups they use to organize observations. They use a variety of procedures to help them devise observation units that are useful, practical, and reproducible. These specific procedures belong to the domain of systematics. As in other aspects of systematics, archaeologists often disagree about terminology or use terms inconsistently. To reduce confusion, the following discussion mainly follows the terminology of Dunnell.
This section will leave aside those kinds of system-atics based on grouping objects by their attributes in favor of the conceptual approach to systematics called ‘classification’. Because this involves defining mutually exclusive categories (‘classes’) of ideal phenomena by specifying the conditions or rules that dictate which phenomena belong, and which do not, to each class, we can create classification in advance of actually examining the artifacts, layers, sediments, or any other entities we want to classify. Not surprisingly, it is usual to have at least some idea what to expect before creating the specifications for the classification. We might, for example, study a pilot sample of our study group in the hope of identifying the attributes that we think might be useful in the classification.
Archaeologists usually employ one of two different arrangements to create classifications. One of these involves defining classes by the intersection of two or more dimensions, while each dimension itself consists of a classification of a single attribute (such as color, shape, or size). This kind of classification, called paradigmatic, will be familiar to readers who have studied languages, as we often classify verb forms by the intersecting dimensions of gender, number, and tense. The other proceeds by the successive subdivision of major classes into subclasses, and is called taxonomic. Taxonomies are familiar to those who have studied biology.
By establishing classificatory schemes and the rules for assigning artifacts to each class in advance, archaeologists can set up templates that help lab staff, including relatively inexperienced volunteers in some cases, sort artifacts quickly and accurately.
Sorting
Sorting of artifacts is a common laboratory practice in archaeology, with archaeologists often doing at least preliminary sorting almost from the moment they remove artifacts and other materials from their archaeological contexts (e. g., deposit in a site). As this involves assigning items to preconceived categories, it entails use of classification.
It is easy to set up the lab in ways that help lab staff sort artifacts properly. For example, many labs that need to sort lithic debitage dedicate a table to this process and mark the table surface with a grid of painted or taped lines to create a series of labeled rectangles, one rectangle for each class in a classification. A set of instructions taped to the table makes it clear how lab staff should decide where to assign each artifact by outlining the rules that dictate membership in each class. For example, one class in a paradigmatic classification could be marked on the table by the rules: ‘flake, incomplete, platform present, unretouched’. Alternatively, a similar class in a taxonomic classification can be clearly marked as a subset of ‘unretouched flakes’, which are in turn a subset of ‘unretouched debitage’ in a grid of nested boxes (Figure 1).
Lab workers can then quickly place each artifact, as they remove it from a bag or tray, on its appropriate square. After they have placed all the artifacts from a given context, it is then easy to count the number in each category and enter that information on a paper form or in a computer database.
Measurement
Sorting and typology involve a kind of measurement at the nominal scale, but archaeologists are often interested in measuring differences in magnitudes: for example, comparing the lengths of projectile points in millimeters, the densities of inclusions in pottery fragments, or the ratios of barium to aluminum in samples of pottery fabric. These involve measurements at the interval and ratio scales, which archaeologists can use to group artifacts, summarize the characteristics of groups, or define the rules for classes, among other purposes. Calipers and balances are among the most common tools they use to make such measurements (e. g., analysis of artifacts: lithic analysis).
Other common, simple tools are paper or acetate lithic recording charts, and diameter charts (see Lithics: Analysis, Use Wear).
World History
