Reindexing a research repository from the ground up: adding and evaluating quality metadata.

This article details the outcomes of the 'National Learning and Teaching Resource Audit and Classification' project, commissioned by the Australian Government's Office for Learning and Teaching (OLT). The project used a range of methodologies to reorganise the OLT's Resource Library (http://www.olt.gov.au/resource-library), constructing and selecting an optimal set of metadata elements, along with certain vocabularies for these elements, and then reindexing the content of the Resource Library utilising the new schema and vocabularies. This paper reports on a before-and-after evaluation of the Resource Library's search performance through an information retrieval experiment based on searches logged by the repository's content management system. It was found that the reindexing produced a significant increase in average recall from 25.1 to 37.1% and a significant increase in average precision from 37.6 to 50.4%. The paper also describes the construction of a new controlled vocabulary for the 'resource type' element and confirms the importance of clarity, conciseness, structure and scope in research report summaries for accurate document selection. Further, the paper outlines the audit of the OLT collection based on the frequency of particular Australian Thesaurus of Education Descriptors and Australian Standard Classifications of Education used in the reindexing. [ABSTRACT FROM AUTHOR]