Network analysis
Network theory is one of the tools we use to analyse the diffusion of fired bricks during the Hellenistic period. This investigation has two parts. First, we perform similarity network analysis to identify spatio-temporal patterns and characterise the process quantitatively. Second, we create social models to simulate the process. The aim is to fit social network models to the data in the sense that they give rise to the same characteristics in similarity network analyses as does the real process. We start with the simplest possible models and add complexity only if necessary. In this way we hope to be able to put forward historical hypotheses in a systematic manner.
The software used in each part of the investigtion can be downloaded at the bottom of this page.
A social model of brick diffusion where three types of actors that may adopt and transmit the innovation are present at each site. The may be interpreted as commissioners, builders, and brick makers, respectively.
The first part of the investigation has generated two papers (see Publications). The first introduces the framework of general similarity networks, and suggest appropriate statistical tests. The second paper applies these methods to the database of Hellenistic fired bricks. The second part of the investigation is work in progress. Some preliminary results are presented in the following powerpoint presentation, which also contains the main conclusions from the similarity network analysis. A more comprehensive account of these matters is submitted to Journal of Greek Archaeology, and will hopefully be published in fall 2016.
(Note that explanatory texts are provided below each slide. Some slides contain movies that show simulated diffusion processes. Place the cursor on top of the map and then click the play-button.)
General similarity network analysis is a novel approach. Therefore we could not rely on existing network analysis software, but had to write our own. The program is written in Matlab, and the main ideas and functions are presented in the following note.
For the sake of transparency, the program may be downloaded below. It runs on Matlab versions R2009a-b, but we cannot guarantee that it will work in older or newer versions.
Unpack the files to some directory X, change directory to X in the Matlab command window, and then enter "Brick_networks" in the command window. The software is provided "as is". The organisation of the files is poor. Explanations are often lacking. The statistical analyses cannot be directly reproduced since we have been continuously changing the files during the course of our work.
The corresponding program that uses a social model to simulate the diffusion can be downloaded here.