Internet Archaeol. 16. Rajala. Data and data models

3.2 Data and data models

'Archaeology is the quintessential candidate for the use of GIS. All our data are spatially referenced, often in three dimensions. We deal with data at many levels of spatial resolution from the artifact to the culture area. Context, the spatial relationships of artifact to artifact, is the bread and butter of our knowledge gaining enterprise'
Zubrow 1990a, 72

Early archaeological GIS discussions centred around the existence of two different data structures, vector and raster. These data models were adopted from outside archaeology and archaeological categories were made to fit into these standards. Vector format presents data as 'a formal description of real world, usually in the form of geometric shapes' whereas raster format 'comprises a number of samples of something, usually taken at regularly spaced interval' (Wheatley and Gillings 2002, 32). These different data formats have their own specific suitability according to different situations, something that was already acknowledged by Savage (1990). He suggested that the vector approach is more satisfying for the display of certain types of features when real world spatial conditions could accurately be presented as lines or definite areas. Savage (1990) perceived the vector format as introducing a highly precise, possibly misleading, interpretative element into the data. In the case of raster data models, the loss of detail is the main problem. However, he rightly suggested that the quality of archaeological data was the critical problem. During the early days of GIS there was an absence of truly uniform data quality standards.

Zubrow (1990a, 72) saw the relationship between GIS and archaeological data in more optimistic terms and suggested that GIS would lead to 'theoretically sophisticated, complex data oriented work'. GIS could be used to deconstruct the typical presentations and definitions of archaeological regions and archaeological sites. Instead of emphasising problem areas, Zubrow (1990a, 68) accentuated possibilities in 'pointillism' where all data could be presented in point form, regrouped and reconstructed into new categories. Through GIS, regional siteless archaeologies could be constructed, where artefacts would form the object of study. Part of the GIS work related to field survey projects fulfils some of this analytical potential (cf. Gillings and Sbonias 1999) but the theoretical development of these concepts has happened mainly outside GIS studies (e.g. Bintliff and Snodgrass 1985; 1988).