Practical applications of stand-off annotation
Larson, V. Jijkoun, Jobst Löffler, E.F. Tjong Kim Sang · 2007
An information system that makes use of stand-off annotation stores metadata separately from the data they describe. System architectures separate metadata from data in order to cope with heterogeneous annotations or with multimedia formats. This paper discusses some of the practical aspects of implementing an information system with a stand-off architecture. Two systems that use stand-off annotations are described. The first is a prototype radio archive that provides users with content-based access to archived radio broadcasts. This system uses stand-off annotation to store structural metadata describing the broadcasts, which is used for interactive presentation, as well as speech recognition transcripts, which are used for search. The second system is a question answering system that searches a large text corpus in order to identify spans of text that provide answers to user questions. This system uses stand-off annotation to store metadata generated by a series of different linguistic analysis tools. The final section of the paper treats practical aspects of implementing a retrieval system for a diachronic language corpus. Similarities and differences with the prototype radio archive and the question answering system are discussed.