Contextual Metadata in Digital Aggregations: Application of Collection-Level Subject Metadata and Its Role in User Interactions and Information Retrieval

Abstract

A number of digital libraries that aggregate multiple digital collections are now generating subject metadata to describe intellectual content of entire digital collections as integrated wholes and to provide context for individual digital objects within them. However, the utility of this important contextual metadata has not been empirically evaluated. The exploratory study reported in this article examined and compared collection-level subject metadata in three large-scale aggregations of cultural heritage digital collections in the United States and the European Union and analyzed the role of collection-level metadata in information retrieval in digital aggregations based on user search queries derived from transaction logs. A small-scale targeted user study, which combined interviews and observations of users interacting with an aggregation, was undertaken to complement evidence-based content analysis data. The study revealed considerable variability in two indicators: consistency of applying controlled-vocabulary collection-level subject metadata elements beyond topical and value length of metadata elements. Both free-text and controlled-vocabulary subject metadata were found vital in answering search queries of aggregation users. Users also expressed preference for viewing complete structured collection-level metadata records, which include subject metadata. Results of this study prove importance of provision of collection-level metadata in general and subject metadata in particular to enhance user experiences and information retrieval in digital libraries.

KEYWORDS:

• collection-level metadata
• contextual metadata
• digital libraries
• information users
• subject access
• subject metadata

ACKNOWLEDGMENTS

The author wishes to thank members of the research and implementation team of the IMLS-funded Digital Collections and Content project at the University of Illinois at Urbana-Champaign, especially Dr. Carole L. Palmer and Dr. Allen Renear for valuable advice and feedback on preliminary drafts of this paper and Amy S. Jackson for explaining Opening History collection metadata practices. The author also wishes to acknowledge the support of Sally Chambers and Christa Maher who provided The European Library and American Memory collection metadata records for analysis and answered numerous questions.

Notes

1. http://www.ukoln.ac.uk/metadata/rslp/schema

2. http://www.loc.gov/ead

3. http://www.niso.org/workrooms/mi/Z39-91-DSFTU.pdf

4. http://dublincore.org/groups/collections/collection-application-profile

5. http://memory.loc.gov

6. http://imlsdcc.grainger.uiuc.edu/history

7. http://www.theeuropeanlibrary.org

8. http://www.loc.gov/standards/mods/v3/mods-collection-description.html

9. http://www.loc.gov/rr/print/tgm2

10. http://www.ukoln.ac.uk/metadata/rslp/schema

11. http://www.thegateway.org/about/documentation/gem-controlled-vocabularies/vocabulary-subject

12. http://www.getty.edu/research/tools/vocabularies/aat/index.html

13. http://www.loc.gov/rr/print/tgm1

14. http://www.getty.edu/research/conducting_research/vocabularies/tgn

15. http://www.theeuropeanlibrary.org/handbook/Metadata/tel_ap_cld.html

16. The European Library aggregates both digital collections and catalogs/finding aids to physical collections.

17. http://www.memoria.sk

18. Only Subjects and Objects controlled-vocabulary subject metadata fields are required in Opening History collection metadata scheme. However, the optional Temporal Coverage and Geographic Coverage fields are also used in 100% of the records.