Exploring the richness of collection-level subject metadata in three large-scale digital libraries

Abstract

A growing number of digital libraries worldwide are now generating collection-level metadata to describe entire digital collections as integral wholes. This paper reports results of the study that used an in-depth comparative content analysis to assess free-text and controlled-vocabulary collection-level subject metadata in three large-scale digital libraries in the European Union and the USA. As observed by this study, the emerging best practices in creating collection-level subject metadata include: (a) describing collection's subject matter with mutually complementary values in controlled-vocabulary and free-text metadata; (b) encoding a variety of collection properties in free-text metadata, including both subject properties (topical, geographic and temporal coverage, and types/genres of objects) and non-subject information: title, size, provenance, collection development, copyright, audience, navigation and functionality, language of items in a digital collection, frequency of additions, institutions that host a collection or contribute to it, funding sources, item creators, importance, uniqueness and comprehensiveness of a digital collection.