Beyond size and search: Building contextual mass in digital aggregations for scholarly use

Abstract

At present there are no established collection development methods for building large-scale digital aggregations. However, to realize the potential of the collective base of digital content and advance scholarship, aggregations must do more than provide search of sizable bodies of content. Informed by empirical understanding of scholarly information practices, the IMLS Digital Collections and Content project developed an aggregation strategy for building Opening History, one of the largest digital cultural heritage aggregations in the country. The strategy applied policy-driven collecting, based on the principle of contextual mass, and conspectus-style evaluation of collection-level metadata to identify strong subject areas within the aggregation. Analysis of density, interconnectedness, diversity, and small/large collection complementarity determined subject concentrations and thematic strengths to be prioritized for future collection development and used as organizational structures for browsing and visualization. The approach models how scholars build their own personal research collections, as they follow leads from collection to collection across institutions near and far, and adds value that cannot be achieved through conventional retrieval and browsing at the item-level.