Perches, Post-holes and Grids

TL;DR

This paper investigates the hypothesis that Anglo-Saxon building layouts were based on grid-like planning using statistical analysis of archaeological images, providing evidence for underlying structural regularities.

Contribution

It develops statistical methods tailored to analyze diverse archaeological images, supporting the existence of structured planning in early medieval landscapes.

Findings

Statistical evidence of underlying grid structures in archaeological data

Confirmation of visual impressions of planning regularities

Methodology adaptable to various image types

Abstract

The "Planning in the Early Medieval Landscape" project (PEML) <http://humanities.exeter.ac.uk/archaeology/research/projects/planningintheearlymedievallandscape/>, funded by the Leverhulme Trust, has organized and collated a substantial quantity of images, and has used this as evidence to support the hypothesis that Anglo-Saxon building construction was based on grid-like planning structures based on fixed modules or quanta of measurement. We report on the development of some statistical contributions to the debate concerning this hypothesis. In practice the PEML images correspond to data arising in a wide variety of different forms. It does not seem feasible to produce a single automatic method which can be applied uniformly to all such images; even the initial chore of cleaning up an image (removing extraneous material such as legends and physical features which do not bear on the planning hypothesis) typically presents a separate and demanding challenge for each different image. Moreover care must be taken, even in the relatively straightforward cases of clearly defined ground-plans (for example for large ecclesiastical buildings of the period), to consider exactly what measurements might be relevant. We report on pilot statistical analyses concerning three different situations. These establish not only the presence of underlying structure (which indeed is often visually obvious), but also provide an account of the numerical evidence supporting the deduction that such structure is present. We contend that statistical methodology thus contributes to the larger historical debate and provides useful input to the wide and varied range of evidence that has to be debated.