Google CSE Search
The Google CSE Search constrains the Google Search Engine to a predefined set of sites. Coupling this with a repository registry service allows the user to - in effect - search the content of repositories.
Google CSE is still in the early stages, and one of the features we have tried to use is the 'annotation' feature. The annotation feature is intended to filter or weight differently sites depending on key words (e.g. weight 'Institutional' repository sites higher). We're still working on getting this right, so if you get slightly odd results when restricting the search please bear with us!
Google CSE Search over ROAR Repositories
If you'd like to use ROAR's site listing in your own Google search, you can generate a 'TSV' listing by using action=tsv and cseid=... to specify your Google CSE id (as shown in the Control Panel).