The London Charter is an international initiative to define best practice in the computer visualization of cultural heritage (http://www.londoncharter.org/). Among the principles embodied in the Charter is the need to publish the "paradata" along with the digital visualization of an archaeological artifact or monument. Paradata is defined as "information about human processes of understanding and interpretation of data objects" (http://www.londoncharter.org/glossary.html). 

In the case of 3D digital models that restore or reconstruct lost or damaged artifacts, the paradata often focuses on elements that are uncertain and how the uncertainty was defined and resolved. In this paper, I will present two case studies drawn from recent work by the Virtual World Heritage Laboratory: the 3D data capture, modeling, and restoration of the portraits of the Greek philosopher Epicurus and the Roman emperor Caligula (the latter supported by NEH grant # RZ-51221). In both projects, imperfectly preserved ancient originals had to be reconstructed on the basis of scattered evidence pertaining to the size and position of the head; the position and gesture of the arms; and the color used on the surface. In the case of Caligula, three variants were created, all equally probable, reflecting the input of an international scholarly team of archaeologists and conservators. In the case of Epicurus, twelve variants were generated reflecting the understanding of three specialists on Greek portraiture.