Significant properties of digital objects: definitions, applications, implications (1)

Significant properties are those properties of digital objects that affect their quality, usability, rendering, and behaviour. In an ideal world, free from technical and economic constraints, libraries and archives would preserve their physical and digital collections in their original form with all significant properties intact. Resource constraints and technical limitations, however, often require libraries, archivists, and curators to preserve objects as facsimiles or surrogates in lieu of original materials and to weigh decisions about which properties to preserve against institutional priorities, available resources, limitations of available preservation methods and technologies, and anticipated use. Digital preservation usually entails converting or migrating digital information to current computing platforms, normalising objects and collections so that they are less dependent on specific hardware and software, developing tools to emulate obsolete platforms, or some combination of these approaches in order to cope with rapid obsolescence of computing technology. Any of these approaches may alter the structure, appearance, and behaviour of the original objects. The purpose of our research is to identify the significant properties of digital objects that affect their quality, functionality, and look-and-feel so that custodians can select appropriate methods which preserve those significant properties of digital objects that are deemed important by designated user communities. A formal articulation of significant properties also provides a framework for documenting the impact of transformations of digital objects that may be necessary to ensure continuing access to them and to explain the reasons for such actions.