Issues in ground-truthing graphic documents

Abstract

We examine the nature of ground-truth: whether it is always well-defined fora given task, or only relative and approximate. In the conventional scenario, reference data is produced by recording the interpretation of each test document using a chosen data-entry platform. Looking a little more closely at this process, we study its constituents and their interrelations. We provide examples from the literature and from our own experiments where non-trivial problems with each of the components appear to preclude the possibility of real progress in evaluating automated graphics recognition systems, and propose possible solutions. More specifically, for documents with complex structure we recommend multi-valued, layered, weighted, functional ground-truth supported by model-guided reference data-entry systems and protocols. Mostly, however, we raise far more questions than we currently have answers for.