By Margaret G. H. Mac Lean

In the lexicon of the conservation profession, the word documentation occupies a fundamental place. Yet this important component of the conservation process, increasingly recognized as critical, is less frequently used than discussed—and even more rarely defined.

What exactly is documentation? And what does it have to do with conservation?

Documentation is information. In conservation, this information can take many forms. The documentation of a painting, for example, might be the meticulous description of its present condition, accounts of past conservation, restoration, analysis, and diagnosis, or a thorough graphic, photographic, and narrative record of all work undertaken on the painting. For an archaeological site like an Inca ruin, documentation might include a cartographic survey of the local geography, a photographic and graphic record of the structures and their details (see For the Record: A Conversation with Peter Dorman), a description of the materials on the site, a condition report on the exposed features, or a description of physical threats to the site.

The documentation of a cultural resource—be it an object or a place—can be likened to a medical exam. It provides information that serves as the basis for comparison with subsequent monitoring or as the starting place for an intervention of some kind. A physician would never recommend surgery without assessing a patient's history, symptoms, and condition. Unfortunately, in conservation (and in archaeology), skipping the steps of examination and diagnosis has led to some sad and unnecessary losses.

Preserving and protecting a cultural resource is impossible without reliable information on its condition and without the ability to monitor change. These require good documentation. At the GCI we are working toward increased understanding of the benefits of accessible, effective, efficient, replicable, and accurate documentation. At the same time, the Institute, through its own projects, is producing extensive information about the physical condition of cultural resources and the process of conservation. In doing that, the Research and Applications group of the GCI's Documentation Program is using everything from traditional research and recording techniques to the latest in technology.

A combination of remotely sensed images of Pueblo Bonito, an archaeological site in Chaco Canyon, New Mexico. Prepared by Dominic Powlesland, a GCI consultant, the combined images illustrate the benefits and limitations of various forms of remote sensing for site monitoring—from low-resolution satellite imaging (Landsat, Spot, KFA) to digital multispectral imaging and color infrared photography (CAMS, CIR), both taken from aircraft, to conventional mapping-type photography (AP 1963, AP 1972), also taken from aircraft. Multispectral images provide useful information on the overall ecological characteristics of an area, while conventional photography is better at recording the condition of a particular site.

Increasingly, the Research and Applications staff are involved in planning and managing the recording of all stages of Institute field projects. For example, in the project to conserve the early hominid trackway at Laetoli, Tanzania, it was apparent that reliable documentation would be absolutely necessary if the protective action proposed to the Tanzanian government were to occur. The recommendation to cover the trackway in order to protect it would be acceptable only if the project team created a thorough, accurate, and usable record not only of the processes involved in its protection but also of the trackway itself. Because covering the site would obviously make it difficult to analyze the information it contained, the project team consulted with anthropologists and others who might want to study human locomotion, as well as other issues, in relation to the trackway. A full sense of what was important about the site was necessary to the process of determining the best level of information that needed to be gathered and how best to proceed. Ultimately, the team decided on close-range photogrammetry, complemented by contextual videotaping, and general photography of the processes. The photogrammetry, done by a skilled team from the University of Cape Town headed by Heinz Rüther, is yielding the most accurate three-dimensional images ever generated of the trackway.

Tom Moon, Heinz Rither, and Gaetano Palumbo—members of the Laetoli project team—preparing to photograph one of the 3.5-million-year-old hominid footprints at the site. Photo: Neville Agnew.

A photogrammetric plot of one of the Laetoli footprints.

Other kinds of field projects require different approaches. The stabilization of the earthen bas-reliefs of the Royal Palaces of Abomey is a project that involves a classic approach to recording, built around straightforward photography done before, during, and after the practical intervention. As part of the project, the conservation team is training local curators and museum staff in using photography as a conservation tool in monitoring deterioration at their fragile World Heritage Site. In this undertaking, as in most Institute field projects, the criteria for designing the information strategy are linked to the needs and interests of our project partner. That means asking questions about how the information will be employed and housed and whether local professionals are able to use the same documentation approach.

Some of our research is designed to anticipate needs in the field by testing tools being touted as the latest great innovation and by assisting conservation practitioners to make sound decisions about the technologies they choose. One recent research project resulted in a new combination of hardware and software for on-site recording. The system was taken to the outdoor site of the David Alfaro Siqueiros mural América Tropical, in downtown Los Angeles, and used to make an extraordinarily detailed digital record of the work. The resulting electronic files can be used for graphic condition reports, virtual restoration, condition monitoring, high-quality photographic printing, and many other purposes.

In a related research project, time-lapse video microscopy was employed to record the crystallization of salts and subsequent deliquescence (that is, the return to a liquid state). The results were a graphic and powerful reminder of the disastrous action of salts in fragile materials. This documentation is not only useful in analysis but it can also demonstrate the need for preventive measures, supporting requests for assistance by conservators and stewards of the heritage.

Another example of a research and application project is in the area of remote sensing—any of a number of methods of noninvasive recording for analytical purposes, from ground-penetrating radar to high-altitude photography. Several years ago, spacecraft-generated remote sensing began to be heralded as an efficient way to automate and simplify monitoring of the condition of cultural sites around the world. Because many people working in site protection sought some guidance on how to accomplish such resource-intensive work effectively, investigating the real potential of remote sensing was clearly an important effort. Now, midway through the project, we have found that in this still-evolving field there are many strengths—and some significant weaknesses. The technological landscape is changing fast, and costs are declining precipitously. New options in documentation can come into range quickly. Our task in this area is to demystify this intensely technical area of analytical recording to assist the professional community in making wise choices regarding their use of resources.

The objective of all these activities is to promote documentation as an integral first step in the planning, analysis, intervention, and monitoring phases of conservation and archaeological work. As such, it plays a central role in the effective management of the cultural heritage. We cannot manage or protect what we do not fully understand.

Margaret Mac Lean is the Director of the GCI's Documentation Program.