Background: The governance of common resources was the research area of Eleanor Ostrom, economist and Nobel laureate. The theory was that common resources are over exploited, and their care and sustainability is overlooked by users.

Methods: We took Cochrane as a knowledge commons, and applied Ostrom’s framework to outputs; and then used Ostrom’s Institutional Analysis and Development (IAD) Framework to appraise the resource, the community, and the governance and rules in use.

We then examined the collective-action problems found associated with the 'commons', including free riding, commitment, supply of new institutions (rules and procedures), monitoring and feedback, compliance and dispute resolution.

The analysis was carried out by a specialist in institutional analysis, working with people in Cochrane, drawing on existing documents and interviews.

Results: The quantity of reviews has expanded, with variation in numbers and quality between groups; access remains restricted; and, Cochrane has yet to consider carefully aspects of the permanence of the record.

The IAD framework indicates a degradation of the specialist resource of methodologists and editors; rules in use are informal but well known, with increasingly detailed procedural rules.

Collective-action problems continue to cause problems in the organisation, with free riding being common. New rules and procedures are developed to help governance, but the organisation still has poor feedback mechanisms, and is without clear guidance for dispute resolution.

Conclusions: The analysis aims to provide a framework to reflect on governance of a knowledge commons and help more clearly articulate the problems arising in an established knowledge commons, and areas that need to be resolved to avoid degradation of the product and the resource.