Philosophy of ARK
Archaeological recording practices vary from site to site, throughout the world. Each system is developed to address site-specific questions and to satisfy individual research agendas. This should be encouraged and embraced—recording systems should be easily adaptable to ongoing or new research questions, and the data structure should not limit or even influence the range of questions that can be investigated or the resolution of the data that can be recorded.
The Archaeological Recording Kit (ARK) is a web-based system built on commonly available open source software that is designed to be able to adapt to any digital or paper-based recording system. ARK includes data-editing, data-creation, data-viewing and data-sharing tools, all delivered using a web-based front-end. ARK also integrates the spatial data that is created on an excavation using Geographic Information Science (GIS). All spatial data is digitised and linked to the data base, making spatial attributes an integral part of the overall data-model.
ARK uses a hybrid of the Entity Attribute Value (EAV) data model and a traditional relational database model enabling great flexibility in what is recorded. By ensuring the ARK data structure is as non-prescriptive as possible the system effectively allows the users to define their own concept of ‘stratigraphic unit’ or ‘context’ or ‘basket’. In fact users of the ARK system could choose to not even record SUs at all.
The ARK concept of stratigraphic units is effectively a collection of fragments of data (spatial extents, texts, numbers, dates, etc.) which are grouped together under one number. By opening the data structure we are allowing the ARKadministrators to define what they see as a stratigraphic unit, to choose to attach whatever data fragments they want to the ‘number’. Or to choose to not use stratigraphic units at all – and treat room or wall or ditch or photo or person as the principal concept and attach fragments of data to these. ARK is built specifically to allow this type of choice and to ensure that the structure of the data model itself is not restrictive and ultimately influencing the outcome of the research. The design, concept and implementation of the recording system is once again in the hands of the directors of the excavation, and not beholden to the limitations and restrictions commonly set in place by the database designer.
Geographic Information Systems (GIS)
The spatial component of the archaeological record is essential in building an understanding of past activity on a given site. Many excavations rely primarily on hand drawn or computer drawn plans, such as those produced by AutoCAD or Illustrator. However drawing plans using these platforms produces a static result that cannot be used for further spatial analysis and are not easily linked to databases. GIS provides a dynamic and flexible environment, attributing spatial data to be tied in to the rest of the data, and allowing the archaeologist to make better use of carefully recorded information.
Spatial data stored in ARK is displayed at the top of the scheda under the site code, SU type, and SU number. The amount of spatial data displayed depends entirely on the nature of the project. This often includes some sort of classification of the location of the SU based on a set of areas such as trenches, zones, rooms, or gridsquares. Other information, such as the area of a given SU or the minimum and maximum levels recorded, can also be displayed automatically if needed.
The spatially integrated nature of ARK allows this information to be presented automatically upon the digitisation of plans. This means the data entry process is not slowed down by re-entering information already available spatially. If the location of a SU is known, and the extent of a room is known, then it is already possible to determine whether the SU falls within or outside that room without re-entering this information.
In order for this spatial information to be integrated successfully, it is integral that digitising of archaeological plans take place concurrently with excavation. As soon the digitised records have been uploaded to the server, the relevant SU information will appear on the SU sheet. This offers the excavation team a better understanding of the site during digging, instead of waiting until a post-excavation data entry and digitising phase to gain this understanding.
The project at Villa Magna uses ESRI’s ArcGIS for importing survey data, digitising, and manipulating spatial data. Although many other platforms are also available, ArcGIS offers a friendly user-interface that is easy to learn and well-suited to the digitising process. For further information on how to use ArcGIS, please consult the ARK help files.