For most of the repository content, the BASE search engine indicates an "unknown access" status.
Of course, unknown does not necessarily mean restricted or no access.
restricted/no access to full text) as a browse and/or search functionality and that indicate the exact number of results (retrieved items) were selected.
Additionally, we conducted a detailed search and/or browsed on each site for specific document types: articles, books and book chapters, conference proceedings and communications, reports, Ph D theses, and working papers (unpublished).
So, what can we conclude about content with restricted access?
Are repositories more open for some document types than for others?
Institutional repositories (IR) have been defined as "tools (...) for collecting, storing and disseminating scholarly outputs within and without the institution" (Jain, 2011) and as "a set of services (...) for the management and dissemination of digital materials created by the institution and its community members (based on) organisational commitment to the stewardship of these digital materials" (Lynch, 2003).
They serve "the interests of faculty researchers and teachers by collecting their intellectual outputs for long-term access, preservation and management" (Carr et al., 2008).
The Open DOAR directory warns users of its repository content search engine that "full texts are not available for most results" but does not provide any statistics.
Operated by the Bielefeld University Library, the search engine BASE provides more than 50 million documents via the "Open Archives Initiative Protocol for Metadata Harvesting" (OAI-PMH).