The distribution maps

• The mapping is based on hectads or 10x10 km squares. These are based on the grid lines of the British National Grid.
• One point on the map indicates the presence of the ware on one or more sites within a hectad.
• Each site may have yielded a single example of the ware, or (more usually) many specimens.

A more detailed mapping interface would take into account more of the richness of the underlying distributional data, such as the relative or absolute abundance of the ware, the date of the assemblages and the functional and social character of the sites.

Sources of the data

• The bibliographies published in the Journal of Roman Pottery Studies. The early volumes of this journal, including the bibliography, are available online at the website of the Study Group for Roman Pottery.
• The catalogue of Romano-British pottery kiln sites published in the microfiche gazetteers in the publication by V.G.Swan The pottery kilns of Roman Britain (HMSO, London, 1984, Royal Commission on Historical Monuments: Supplementary Series 5.
• Other sources, particularly reports on individual sites or wares.

Problems with the data

• Some wares are likely to be severely under-recorded in the database, notably common types such as sigillata and amphoras.
• There are likely to be some misidentifications recorded in the database, reflecting problems with the original sources. For example, there is likely to be confusion between some classes of fine ware.