Special Interest Areas (SIAs)
There were various reasons for designating an area as an SIA:
As Special Interest Areas typically extended at least 500 m in each direction, a single 50 m wide transect was clearly not a sufficiently large sample to answer questions about variations in material culture. In such situations the transect was broadened so that the survey units covered as much of the intervening area as was needed; this approach we termed 'block survey'. Usually the units were contiguous, conforming to field boundaries where these existed.
Apart from the greater number and extent of the survey units, the methodology used in block survey was identical to that of the transects, in terms of fieldwalking, collection strategy, and the recording of information. This means that the data from transects and block survey are totally compatible. Because the different SIAs varied greatly in character, several different techniques were used to investigate them, usually in combination. These included a general walkover; the investigation of individual POSIs; block survey; and additional sample transects.