
The sources used included the National Archives of Scotland, The Acts of Parliament of Scotland, Ayr Burgh Accounts, Calendar of State Papers Relating to Scotland and Mary Queen of Scots, Court Books of Orkney and Shetland, and many other page-turners. The problem with these sources is that they cannot easily be used by themselves. If you’ve ever worked with large data sets, you’ll know that it is nearly impossible to process it all by hand. The maps utilized APIs and online resources to achieve their purpose.
The Geographical data and ArcGIS Online maps were produced by Emma Carrol, a Geology and Physical Geography undergraduate student at the University of Edinburgh. She was the primary resource for the location of witches. They called her the ‘Witchfinder General’.

The ‘Witchfinder General’ had resources to achieve her goal of… finding witches. She used Wikidata, a sister site of Wikipedia; this site serves to be a machine-readable resource for tech-savvy people interested in their various data sets. The data was visualized using Leaflet or ArcGIS Online. These programs make it easy to geographically project witches onto a map:
As stated before, Wikidata is a site that takes data from Wikipedia and makes it machine-readable. Here is an example of a page on Wikidata that is easily readable using an API to scrape data:

The methodologies of this project are very clearly communicated. By accessing the About > References page of the Witches site reveals another site that lists all of the resources that were used in gathering data. The only critique to be had is that they were not careful with their links because some of the links are broken, or the URLs have been bought for a different purpose than originally intended.