[NPS Arrowhead] U.S. Dept. of Interior National Park Service Archeology Program
Quick Menu Features
* Sitemap * Home
  Managing Archeological Collections Curation in the Field and Lab Distance Learning

Laboratory sampling and management

(photo) Archeologist processing artifacts in the lab.
Artifact processing at the Stabilization Laboratory of the U.S. Army Corps of Engineers, St. Louis District's Mandatory Center of Expertise for the Curation and Management of Archaeological Collections. From the photograph collection of the U.S. Army Corps of Engineers, St. Louis District.

Once a collection has made it to the archeological laboratory, whether it is at the site or off-site, more decisions and actions affect the proper long-term care and management of the collection. Again, it is essential that all decisions and actions are well documented and become part of the project record.

The first step of good collection processing in the lab is the use of appropriate cleaning methods. The different classes of material remains should be cleaned in the appropriate manner. Most objects, especially metals, should not be cleaned with water, detergents, or other liquids. In fact, an untrained individual should not clean metal objects. Dry brushing with a soft bristled brush is best for many object classes, including dirty field records. Vigorous brushing can destroy decoration or the surface finish on many materials. Water should only be used to clean non-porous objects, such as lithics or certain ceramics. Some objects should not be cleaned if they are going to be used for dating or other scientific analysis. For example, lithics with surfaces that may have residues remaining from use should not be cleaned.

Statistical sampling and culling of material remains, including non-cultural soil, dating, or other samples, usually occurs in the laboratory rather than during field collection as discussed in a previous sub-section. There are always inadvertently collected objects that are found to be non-cultural after they are cleaned, which are culled from the collection by tossing them in the trash.

A statistical sampling procedure, which should have been first presented in the project research design, may be implemented in the lab. Careful use of statistical sampling procedures results in a collection of appropriate and manageable size that still has maximum research, interpretation, and heritage value and potential. Improper sampling (or not sampling at all) can lead to a collection that is either too big due to unnecessary redundancy, too small due to oversampling, or not well organized for optimal use by researchers, educators, curators, or culturally affiliated groups.

The first step to statistical sampling in the laboratory is a preliminary analysis of all material remains. This includes separating, counting, and weighing the different classes of objects to determine the range of variation of each. A specialist in the object or material class should work with the principal investigator to determine the exact extent of the variation and what object features should be used for classification and analysis. The specialist and principal investigator should then determine if statistical sampling of artifacts should occur. This decision should be based on:

  • evaluation of the relative quantities of objects in each artifact class and how they are distributed over the project area;
  • the range of variation within a class;
  • the scientific methods that could be used to study the objects (and the number and variety of objects needed for those scientific methods); and
  • the potential of future research by other specialists and colleagues (although this can never be fully anticipated).

If the principal investigator supports the recommendation to statistically sample an object class, the next step is to determine the appropriate sample size. This will generally depend on the anticipated needs of researchers, educators, curators, descendent communities, and others, both currently and in the future. Estimates should take into account any destructive analytical methods that may be used, which impact the total sample size available over time.

Due to the variables listed above, sample sizes may differ for each artifact class. Important diagnostic artifacts should be retained (sampled at 100%), while more common, highly redundant artifacts may be sampled at 10, 25, or 50%.

Whatever sample size is determined, it is essential that all decisions are well documented so that the repository staff and future researchers, interpreters, and culturally affiliated groups can properly understand the history of the collection in order to make maximum use of it.

  back  next