In this chapter we will examine some issues concerning the formation of archaeological deposits and the ceramic assemblages they contain. First, we will consider one of the more important of the factors governing the relationship between the ceramics in use and those recovered from archaeological contexts – the use-life or life expectancy of the material. The value of sherd-link data is next discussed, followed by considerations of pottery collected from field walking and the role of quantification in the examination of site-formation problems.

Pottery Life Expectancy

There is a small but valuable body of ‘ceramic census data’ collected by ethnographers and others detailing the types of pottery in use in individual households, which archaeologists have drawn upon in several ways as an aid in their interpretation of archaeological assemblages (Kramer 1985), although Tani and Longacre (1999) argue that the inventory method overstates mean use-life.

The most useful of these studies provide lists or inventories detailing not only the types and numbers of vessels in use in particular villages, compounds or houses but also records of their age; from the latter may be derived estimates for the life expectancies of vessels of various forms or functions. An early study by Foster (1960) of life expectancy of pottery in Tzintzuntzan (Mexico) identifies five basic factors influencing breakage rates:

1. (i) the basic strength of the vessel;

2. (ii) the vessel function – its use as a cooking vessel, water jar, storage jar and so on;

3. (iii) the method of use, such as the type of stove;

4. (iv) the context of use – the care taken by the user, the activities of children, animals and so on;

5. (v) the cost of the vessel.