The vast bulk of Professor Barley's papers consist of correspondence connected with the work of various committees on which he served, and projects with which he was involved. The subject matter is both archaeological and historical. Within the original collection, a particularly important and interesting section is Professor Barley's research material on the Plough Monday plays of the East Midlands. The section includes texts from Derbyshire, Nottinghamshire, Lincolnshire, Yorkshire and Leicestershire, as well as miscellaneous notes and correspondence collected from informants. There is also a file of photocopied material collected by Mr Peter Millington for his research into the folk plays of Nottinghamshire and Derbyshire.
The principal series in the subsequent accruals (catalogue still in preparation) concerns his research notes on vernacular architecture, divided into county series. The papers also include records of his involvement in various bodies, notably the Area Advisory Committee for Archaeology and the York Archaeological Trust.