The standardised recording and quantification of Roman coins are necessary if the analysis and study of Roman coinage is to be consistent, reliable and informative.
How analysis takes place will depend on a combination of variables, for example the type of archaeological project, size and condition of the coin assemblage, and the nature of the excavated settlement, etc. Innovative analytical methods have led to significant advances in the understanding of Roman coins in the past, and invention and experimentation should be encouraged. It is also important, however, that analysis is focused on producing evidence-based results that lead to meaningful insights about coins as archaeological artefacts.
The conventional analytical methods applied to Roman coins were developed from the 1970s. All Roman coins are identified primarily as numismatic objects and their dating is almost always determined by when they were made at the mint. This allows their arrangement into a chronological sequence, tabulated or represented graphically, from which it can be seen which Issue Periods generate more, or fewer, coins. The significance of such variations in these coin ‘profiles’ can be identified when they are compared to the broader background of coin recovery, which in the case of Romano-British site-finds is known as the ‘British Mean’ (this approach was developed by the mid-1990s and is a chronological sequence of averages derived from coins from 140 archaeological sites). New ‘Mean’ sequences have appeared more recently that are average values of alternative coin corpora, such as the ‘PAS Mean’, the ‘Walton Mean’, or county ‘Means’ (eg, ‘Suffolk Mean’).
Big Data are not necessarily good data, however, and studies of Roman coins perhaps have tended to concentrate on process, rather than what analysis is intended to achieve. In theory, Roman site-finds have much to contribute to the understanding of their functions as monetary, as well as cultural and social, objects, but the currently prevailing methods of analysis cannot explore these important aspects of their biographies. The analysis of Roman coins exclusively by their dates of production is also problematic.
Dots filling maps, or graphs comparing when coins were struck with a variety of other data aggregations, are tried and tested methods, but there is much to be learned from analysis that examines Roman coins as archaeological artefacts, with cultural and social value in addition to their use as money. Greater focus on the archaeological origins of Roman coins, how they were deposited and with which other artefacts, would lead to a better appreciation of when Roman coins were deposited and under what circumstances, thereby improving understanding of the activities and actors involved in their loss, disposal or deliberate deposition.
Good data can be used to explore research themes concerned with Roman coins as monetary objects (ie, when they were struck and their use as circulating currency), as well as how they had been used when they became archaeological artefacts. Accidental loss is one explanation, but there are others too that might better fit the archaeological evidence, requiring an understanding of site formation processes to generate integrated, stratigraphic analysis of Roman coins. Exploratory inter-site comparison of Roman coins, whether from individual or multiple sites, or larger collections and corpora, also can deliver important new insights about circulation and use, although it is of course necessary to establish that the method is based on consistently reliable, and widely accessible, data, and also that the results are meaningful.