Artifacts and artifact classification
Artifacts and artifact classification
Artifacts are often the most intriguing part of archaeological research. Whether priceless or common, they are key to deciphering the archaeological record and information about how people lived in the past. Most of the information from archaeological excavation is gathered from an artifact’s context, or where it is found, and with what other items it is recovered. Artifacts, and their context, help archaeologists describe and compare aspects of past cultures, as well as form a chronology of those cultures, although there are limitations on how much scientific information artifacts alone can provide.
An artifact is any object that was intentionally designed and shaped through human effort. Some artifacts are discovered by accident, for example, by a farmer plowing his field or by a construction worker digging a foundation. However, archeological excavation and artifact retrieval always proceed by well-established methods designed to record as much information as possible about a site and its artifact assemblage, or group, of recovered objects.
When collecting artifacts from an archeological site, archeologists endeavor to establish and document the context in which an artifact was found. To understand context, they must take care to document the artifact’s exact horizontal and vertical positions, its relationship to the stratum in which it was found (its stratigraphic position), and any cultural factors that contributed to its location. Each step of the excavation is recorded with detailed maps and photographs. Some archeologists use specially prepared data sheets to record information about recovered artifacts that they later enter into a computer. Recovered artifacts are placed in bags (and sometimes assigned field numbers) before being sent to a laboratory for analysis.
Besides artifacts, archeologists may take sediment samples from a site back to the laboratory for fine-screening. This allows artifacts that typical field-screening techniques would otherwise miss to be recovered. For example, sediments may provide microscopic pollen grains that aid paleoclimatic reconstructions. Material from ancient hearths may contain seeds, hulls, and small animal bones that help archeologists decipher the diet of that site’s occupants. Charcoal samples can be retrieved for carbon-14 (radiocarbon) dating.
In wet or submerged sites, artifact recovery is more difficult, because artifacts can disintegrate when dried too rapidly. Even in dry caves, some recovered materials may require special treatment to be preserved. It is important in these cases for an archeological conservator to be present at the excavation site to assist in the recovery of artifacts. Delicate pieces may be protected in plaster, polyurethane foam, resin, or latex.
After an artifact’s position has been mapped and recorded in field notes, it is taken to the site laboratory to be cleaned and labeled. Artifacts are then sorted according to type of material—e.g., stone, ceramic, metal, glass, or bone—then into subgroups based on similarities in shape, manner of decoration, or method of manufacture. By comparing these object groupings with the stratigraphic positions in which the objects were found, the archeologist has a basis for assigning relative ages to the objects.
The objects are finally wrapped for transfer to an off-site laboratory. This processing should be performed quickly so that documentation of all artifacts found at the site may proceed without delay. Each specialist involved in an excavation will usually write a report of his or her findings at the site. These reports will later be collectively published in a scientific journal or book as the site report. Often archaeologists also detail how the site should be managed, further excavated, or preserved.
Typological analysis classifies artifacts into types based on observable traits such as form, method of manufacture, and materials. Classification should not be based on an artifact’s function, because this often cannot be determined unambiguously. According to this concept, within any given region, artifacts that are similar in form or style were produced at about the same time, and stylistic changes are likely to have been gradual or evolutionary. Typologic categories are, however, only arbitrary constructions used by archeologists to come to terms with the archeological record. There is consequently no single, best way to classify artifacts into types.
A typologist first classifies artifacts in terms of attributes, for example, raw material, color and size, then classifies them using mutually exclusive characteristics, called attribute states. Thus, ceramic pots could be sorted on the basis of shape, for example, into groups of bowls, jars, and plates.
While the typologist is generally satisfied using attribute types to describe artifacts, the goal of archeological classification is to so completely describe artifacts that they can be easily compared with objects from other sites. Unfortunately, this is much easier said than done. Because typology is largely based on an almost intuitive ability to recognize types, or requires several typological guides or other comparative resources, it has been refuted by practitioners of more rigorous analysis. By employing mathematical and statistical analyses, typologists have tried to demonstrate that attribute types are not arbitrary, and that their use provides significant, reproducible results.
When statistical methods were introduced into this field in the early 1950s, typologists claimed that artifact types in each culture were inherent, and that they could be determined by statistical analysis. Since that time, however, this assumption has been repeatedly questioned by those who doubt that the existence of absolute types can or will ever be verified. The advent of absolute dating techniques has also given archeologists a much less arbitrary basis for classifying artifacts. While typology is no longer the standard means of dating the components of most artifact assemblages, typological analysis is still one of the most useful means of describing and comparing various artifacts.
In recent decades, archaeological excavation and analysis of more recent historical sites has increased. Urban, or industrial, archaeology focuses on artifacts produced during and after the Industrial Revolution, especially those sites associated with manufacturing or related urban neighborhoods. Many artifacts recovered from these sites have decorations, maker’s marks, or shapes that are easily identifiable because they are documented in the historical record or resemble something still used today. For example, historic archaeologists of the modern period sometimes rely on antique guides, old photographs, or factory archives to identify and date an object. While more definite because of the wealth of collaborative material, this type of analysis is still a form of typology.
Artifact— A man-made object that has been shaped and fashioned for human use.
Radiocarbon dating— A technique that provides numerical ages for the remains of plants and animals (for example, charcoal, wood, or bone) based on the radioactive decay of carbon-14 in a sample.
Stratigraphy— The study of layers of rock or soil, based on the assumption that the oldest material will usually be found at the bottom of a sequence.
Stratum— A geological or man-made deposit, usually a layer of rock, soil, ash, or sediment. Plural: strata.
Typology— The study of artifacts based on observable traits such as form, methods of manufacture, and materials. Classification should not be based on an artifact’s function, because this can not be determined unambiguously.
Lyman, R. Lee., and Michael J. O’Brien. Seriation, Stratigraphy, and Index Fossils—The Backbone of Archaeological Dating. New York: Kluwer Academic Publishers, 1999.
Bradbury, Andrew P, and Michael D. Richmond.
“A Preliminary Examination of Quantitative Methods for Classifying Small Triangular Points from Late Prehistoric Sites: A Case Study from the Ohio River Valley.” Midcontinental Journal of Archaeology (Spring 2004).