Merging Metadata and Content-Based Retrieval
Educational digital libraries employ resource discovery systems that are aimed at providing educators and learners with curriculum materials to support learning in both formal and informal settings. The article describes a "hybrid" educational resource discovery system, which combines metadata and content-based retrieval methods. This hybrid system was implemented and evaluated in the context of the Digital Library for Earth System Education (DLESE). A pilot study was conducted to compare this hybrid system with an existing metadata-based system, with the aim of finding out if the hybrid system helps educators locate relevant resources with less effort. The results of the study suggest that the hybrid system decreased the variability in the number of user actions required to locate learning resources. The hybrid system interface featured embedded links, pointing to inner pages within a larger compound learning resource; study participants made use of these embedded links to locate individual learning objects.