METHODS

The theory underlying the methods used by the author assumes that whenever a vessel was broken a similar replacement was obtained, although of course if this was literally true there would be no change at all in the types of pottery used. It follows from this theory that the relative frequency of vessel types and sources found in an assemblage will be directly proportional to their relative frequency of purchase. This assumption underlies all the work in this study and it is neccessary to point out that the work of Schiffer (1972 and 1976) suggests that it is only one possible interpretation of the relationship, and that other factors, such as disposal patterns and functional variation within and between sites, may affect the composition of an assemblage. These factors, and their relevance to medieval pottery studies are discussed below.

In order to interpret the statistical analysis of an assemblage in economic terms only those groups deposited over a very short period of time containing no residual pottery in them should be used. If such a selection policy was carried out rigorously then the number of usable assemblages would be very small. Therefore, poorly stratified and even unstratified collections have been used in this part of the study. The results of their analysis have been interpreted using the better stratified collections as a guide.