‘History Was Here’: NCSA’s technology is helping unlock the mystery of medieval graffiti

05.22.18 -

by Katherine Kendig

Visitors to San Marco Basilica in Venice, Italy are likely to feel a sense of awe: the sheer mass of the thousand-year-old structure and the details of its ostentatious decoration are undeniably impressive. But Mia Trentin, a postdoctoral fellow with the Cyprus Institute, an international partner of the National Center for Supercomputing Applications (NCSA) at Illinois, hasn't spent years studying the soaring architecture and glittering mosaics of San Marco. Instead, she focuses on something many of us would barely notice: the graffiti. Trentin has found over 2,000 individual instances of graffiti at San Marco, in places high and low, hidden and obvious, dating from this century to nearly a millennium ago. While modern graffiti is often seen as destructive to public buildings, historical graffiti is a key to unlocking the past. With the help of NCSA's advanced technology, Trentin can open doors to understanding what life was like in the Middle Ages.

In pursuit of advanced tools for storing, visualizing, and studying the graffiti data she's collected, Trentin spent two months in spring 2018 at NCSA as part of a collaborative partnership between NCSA and the Cyprus Institute that furnishes postdoctoral researchers with joint positions involving both institutions. Trentin's position unites the Science and Technology in Archaeology Center (STARC) at Cyprus with NCSA's Culture and Society research theme. During Trentin's stay, she worked with Luigi Marini of the Innovative Software and Data Analysis (ISDA) team, Donna Cox, Associate Director of R&E and Director of NCSA's Advanced Visualization Laboratory (AVL), and Colter Wehmeier, a graduate student on the AVL team, to pair her ancient data with NCSA's modern technology.

Graffiti may have been ubiquitous in medieval Europe, but if so, most instances suffered the same decay or destruction that their architectural canvases did. Now, Trentin says, nearly all enduring graffiti is on religious buildings, which in many cases had the dual advantages of stone construction and good caretaking. Church walls served as makeshift guest books, wishing wells and answering machines, as pilgrims left signs of their passing, requested assistance from the saints or gave thanks for answered prayers. Trentin observes that graffiti reveals historical attitudes in a way that more formal art and architecture do not, offering a "bottom-up" look at culture at particular moments in history. Trentin recalls tracing graffiti onto transparencies early in her career: "When you do that, you are in the same place that the original person was centuries ago, the point of your pen is doing the same thing—it's a contact point" between the modern researcher and the past. Because medieval graffiti consists primarily of drawings, "it's a sort of suggestion or game—try to guess what I was thinking in that moment."

With help from NCSA, Trentin and others will have a better chance of guessing correctly. Wehmeier, an Illinois graduate student in Architecture with a focus on Digital Cultural Heritage, suggests that integrating Trentin's data with Clowder—a versatile data management system developed at NCSA—was "the obvious answer" because of Clowder's advantages when it comes to storage and access for humanities projects. Clowder will provide a unique database that Trentin and other researchers can use to further their investigations, storing both the graffiti images and the information surrounding them. "Clowder will also let [Trentin] define her own standard vocabulary and metadata definitions," Marini adds, which will allow the user community to perform advanced, targeted searches of the data using their own metrics. Moreover, Clowder's Web Service API enables the creation of a custom web interface "to visualize this information in Clowder in story-based and geospatial views."

Wehmeier and the AVL are currently at work developing that interface. While Trentin is focused on the user experience for archaeologists, Wehmeier says, NCSA is considering "What's the best way to represent this? What do we show and not show? How do we fit the ideas of people in the humanities into the technical framework that software projects have to fit into?" Right now, because location is so important to studies of graffiti, the AVL is focusing on adding an initial 2D "spatializing" of the searchable graffiti with top-down views of sites. "We're not trying to create a singular vision," he notes, so much as "trying to figure out what this [interface] looks like." Features like panoramic views, 3D, and VR experiences are all being discussed as future possibilities for the project.

Virtual renderings of graffiti coupled with historical information about graffiti sites, Trentin believes, will enable researchers to immerse themselves in the context of graffiti without expensive travel, and better understand patterns displayed by countless pieces of graffiti that, in real life, are often difficult to access and not highly visible. "Visualization will make the difference," in studying graffiti, Trentin says. And studying graffiti may well make the difference in understanding an unsung layer of medieval history.