Ensuring open repositories fulfil the discovery needs of both human and machine users is of growing importance and essential to validate the continued relevance of open repositories to users, and as nodes within open scholarly communication infrastructure. Following positive preliminary results reported elsewhere, this submission analyses the longer-term impact of a series of discovery optimization approaches deployed on an open repository. These approaches were designed to enhance content discovery and user engagement, thereby improving content usage. Using Strathprints, the University of Strathclyde repository as a case study, this article will briefly review the techniques and technical changes implemented and evaluate the impact of these changes by studying analytics relating to web impact, COUNTER usage and web traffic over a 4-year period. The principal contribution of the article is to report on the insights this longitudinal dataset provides about repository visibility and discoverability, and to deliver robust conclusions which can inform similar strategies at other institutions. Analysis of the unique longitudinal dataset provides persuasive evidence that specific enhancements to the technical configuration of a repository can generate substantial improvements in its content discovery potential and ergo its content usage, especially over several years. In this case study, COUNTER usage grew by 62%. Increases in Google ‘impressions’ (266%) and ‘clicks’ (104%) were a notable finding too, with high levels of statistical significance found in the correlation between clicks and usage ( t = 14.30 , df = 11 , p < 0.0005 ). Web traffic to Strathprints from Google and Google Scholar (GS) was found to increase significantly with growth on some metrics exceeding 1300%. Although some of these results warrant further research, the article nevertheless demonstrates the link between repository optimization and the need for open repositories to assume a proactive development path, especially one that prioritises web impact and discovery.
