Dividing artefacts into functional groups is a method utilized by Stanley South in his study of sites in Colonial America. Other archaeologists have used this method as well, including some work in Roman Archaeology (e.g. Cool et al 1995, and Gardner 2001). By grouping artefacts into functional groups, in addition to groups formed by material or appearance, we can analyze behavior in the cultural system under study. Because standardized functional groups have not been universally agreed upon by archaeologists, I used South's groups as a starting point and expanded them with additions appropriate for a Roman military site. Functional groups are used in this study to confirm our understanding of the behaviors which took place in the different sectors of Roman military sites, or to change and refine that understanding as well as provide a platform to ask further questions.
Assigning artefacts to functional groups can be problematic. The same artefact, for instance a knife, can have different functions, for example in the kitchen or on the war field. This must be kept in mind when examining functional group results. In an attempt to alleviate this possible problem, artefacts with obviously more than one function, once again a knife for example, were assigned to more than one functional group. Currently only the first functional group assignment is used in the computations on this website, but eventually the ability to use the other assignments will be coded.
The functional groups Decorative Architecture (DA), Animal Remains (ANML) and Not Roman (Not Roman) were not used to compute percentages or percentage means, and their totals were not included in the overall total of artefacts from any site. When Animal remains are collected and studied during an archaeological investigation they often end up overpowering the other functional groups in sheer numbers; much as the Kitchen/Food functional group does. This would not be a problem normally, but Animal remains are very frequently never collected, studied, or included at all in an excavation report. Therefore inclusion of this group would radically skew numbers for a few sites, and not at all for most of the others. Decorative Architecture is not included because the functional group is somewhat arbitrary and once again, its elements are not always included in an excavation report. For example, the finding of nails will often be mentioned, but the numbers of those nails will seldom be given. And Not Roman is not included for obvious reasons.
The problems mentioned above with the Animal Remains category occur with the Kitchen/Food category as well. Some archaeological reports detail every ceramic find in their artefact catalogs. Others only mention weights, or rim sherds, or other kinds of summaries. And still others say nothing beyond mentioning one or two outstanding or otherwise noteworthy ceramic exemplars. In order to include every bit of information possible the type of stratification of the artefacts was given one of several possible categories and that category was used in figuring the functional group numbers. These categories are 'All' which includes all the functional group's items from the sector and functional group; 'Strat' which includes only those items in the group which were found stratified; and 'Good' which includes stratified items in the group from excavation reports with artefact catalogs which were considered complete (i.e. every artefact of that type from the site was included in the catalog instead of only a representative sample).