An analysis and case study of digital annotation

Digital annotation of multimedia objects is an activity central to many important tasks, such as studying, commenting on, indexing and retrieving. Although annotation is becoming widespread, a formal account of it is lacking. We argue that an algebraic definition of the functions and of the data types involved in digital annotation is essential in the design of tools. Moreover, it allows designers to establish syntactic, semantic and pragmatic aspects of the annotation activity. This paper starts this enterprise by providing a formal analysis of digital annotations, seen as special types of documents dependent on the existence of other documents. This analysis allows a distinction to be made between annotations and other types of digital entities. Moreover, we identify operations and procedures that should be enabled by annotation systems. As a case study, the UCAT annotation system is described.