Archaeology Internship in Pottery Typologies: From a spreadsheet to a database
Co-Authors: Donovan Hernandez and Cinzia Perlingieri
How my internship resulted in the digitization and post-processing of an archaeological pottery collection into a typology database
All cultures, both past and present, tend to develop the same things: tools for hunting, for fishing, tools for food preparation, for worship, for art. But while these trends are nearly-universal, their products are always unique. No two cultures make precisely the same spearheads, fishhooks, idols, jewelry, or pottery. Furthermore, no one culture maintains a single style throughout history (after all, fashions may change in few years and every generation!)
In order to understand and interpret these changes, archaeologists accurately classify all aspects of morphology, style, and technology of their finds and sort them into “types”. A “type” is a group of very similar items that is separated by other groups of items by one or more characteristics, and all these groups of similar items (types) are collected into a reference typology. Archaeologists often refer to reference typologies in order to date and interpret their evidence, but also to use common terms that allow them to understand each other and compare data in efficient ways. This applies to most archaeological finds, including pottery.
Pottery is one of the main cultural indicators in an archaeological excavation. It allows us to understand ancient habits, diet, technological skills, and organization of spaces within a house, a compound, and an entire site. Pottery evidence from one site can be used to interpret and date another site, and comparisons between pottery traditions of different sites can help identify cultural contacts. For instance, in Egyptian archaeology large corpora of pottery types have been published that help archaeologists identify and date new sites being discovered all over Egypt. This ability of comparing evidence and using the same definitions based on typologies, makes it possible for archaeologists to formulate hypotheses on ancient societies on a very large scale.
Aksumite pottery and the collection from Bieta Giyorgis
Unfortunately for some areas and regions there are no typologies of reference. This is the case of Aksum. When my coordinator Cinzia Perlingieri started working on Ethiopian pottery several years ago she could not rely on any published reference work, she was the first to systematically describe the ancient Aksumite pottery. Many years of meticulous work have resulted in a large collection of drawings, notes, logs, photos, and in the first typological classification of ancient Aksumite pottery that is now in the process of being published as a printed work and as a web resource. In order to complete this project, many materials that are presently in paper form need to be converted into digital form, and all the different results need to be integrated and harmonized into one managing platform. The publication of this material will greatly help archaeologists working today in northern Ethiopia and neighboring countries, to better understand their finds, to make comparisons, and will dramatically speed up our knowledge of the important Aksumite culture.
And this is where I came in! The goal of my internship was to contribute to the digitization and post-processing of this large pottery collection for inclusion into a digital database. I focused on two critical steps of the larger process: the digital catalog and an integrated database. The first thing we did when I started, was to focus on the end goal of our project, which was: to create a pottery typology from Bieta Giyorgis, which would include standardized descriptions of pottery types and their fabric, images of types (drawings), and external bibliographic references. In order to do this we needed to harmonize and combine the available materials (mostly in paper form… hence the photo below). So we began by making a list of the available data and materials: 1) a spreadsheet with names and descriptions of types, 2) a spreadsheet with fabric descriptions, 3) a catalog of digital images (drawings and photos), 4) a comparative bibliography.
The Digital Catalog
The goal of this activity was to create digital copies of line drawings of pottery types and gather them into a photo catalog with embedded metadata describing their names, basic characteristics and descriptions. Before doing that we needed to match the drawings with the described Types.
The tools I used: Microsoft Excel, ScanMaker 9800XL, Adobe Photoshop Lightroom 5, FileMaker
It all started with a spreadsheet (I am told that this is often the case with legacy archaeological data!). In this spreadsheet (image below) all pottery types were consistently named and described in all their morphological features. The names of the types (Look at column G; “Type Complete Name”) represent the vessels’ Class, Shape Group, Type, and Type Variant. In this way titles could be easily used to determine to which group the object belonged. These same names would inform the file naming convention for the digital files later.
Process of Digital Conversion
To begin digitally converting the drawings of the pottery of Bieta Giyorgis, there must be a conversion of the physical record to a digital file. I used the scanner ScanMaker 9800XL to digitize all the drawings into DNG files (Digital Negative file). The DNG acts as a transporter of metadata, or information embedded into the image. This embedded information would then travel with the photo, which made cataloguing more efficient and the images identifiable. Once the DNG was created, the process of digitization was complete and the use of Adobe Photoshop Lightroom would be needed. Lightroom helps in the manipulation of images. However, rather than changing the original image, Lightroom works on digital copies. This allowed for the original photo to retain its intact information and the digital copy to be used in the database; how cool! so if you do something really wrong you can always start over from the original! After the creation of the digital copy, this copy would then be resized and saved in a separate folder for later use.
Through Lightroom, some of the descriptive fields in the spreadsheet were added as metadata embedded into the images (image below). How I embedded the metadata was simple, I learned it quickly, and a process that was easy to replicate. I could add some information in batches and go into every file for additional specific info on individual types. The “title” of my output DNG files replicated exactly the “Type Complete Name” from the typology spreadsheet.
At this point we had everything we needed to proceed with building the database: conventional naming, full description and curated digital drawings for each type of pottery (YEY!)
And now it came the most difficult part for me. It is not like you learn to build a database in the space of a short-term internship like mine… In fact I didn’t. I received a basic training on FileMaker from CoDA’s staff, enough to understand what I should be learning and how long it would take. But I learned some important basic concepts around building databases, and I was there for part of the magic!
A database is intended to address real-world problems. In our case we needed to translate the needs and the aspects of this pottery typology into the form and language of a semantic database. All the preparatory work we did at the beginning of my internship, was aimed at making decisions about what materials and data would go into the database to make it effective and complete. We answered questions such as: what and how many tables should we create in order to include all necessary data to describe this pottery? Which fields go in which tables? How should they be linked together? The skill by which we made informed decisions about how to combine all the available pieces of this typology together into a database is called “data modeling”.
I leave the description of the steps and features of the database to the CoDA team for another post. Enough to say for now that my work led to this great tool (it is still work in progress):
“I was not digging holes in my archaeology internship. I took the more technical and digital role. My job was to take an archaeologist’s drawings of pottery, digitally archive them, then move these images into a database for worldwide access. Of course, being in Marin, I knew I would not be on the hunt for lost civilizations in the hills. Yet, it showed me the importance of technology within archaeology and its role as an agent for cultural preservation. That very goal was that of the Center of Digital Archaeology and my own. I hope to continue with cultural preservation in my career, whether it is continuing the long held tradition of archaeology or the newest trends in digital archiving.”