Quality assurance is important, as the common perception of freely available online content is that it is somehow inferior to printed or subscription-based content, or at least that its value is unclear. To qualify for OAPEN membership, you need to publish mainly scholarly titles and follow peer-review procedures.
The procedures for peer review vary across borders and publishing traditions. While we do not rank these procedures, we do have minimum requirements: reviewing should be conducted by independent peers and/or editorial boards, and editors (including series editors) should not act as reviewers.
OAPEN requires publishers to describe their peer-review procedures and to make them available for publication on the OAPEN website. The aim of transparency in peer-review procedures is to ensure and promote academic standards, which will benefit all publishers in the long run. A checklist of review procedures will be made available from www.oapen.org.