This article reports results of a 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.

This article discusses the use of network analysis through the creation Metadata Record Graphs to analyze the interconnectedness of subject and keywords in the University of North Texas Theses and Dissertations collection. The analysis compares overlap of controlled terms (Library of Congress Subject Headings) and uncontrolled terms (keywords), as well as the effects of basic format normalization (to simulate editing values for consistency) to evaluate how well subjects connect in the collection.