Over the past decade, open access (OA) delivery of content has seen rapid growth and has proven itself as a viable business model for distributing scholarly content. Increasingly, many publishers are providing OA options to authors, and a growing number of funding agencies are mandating that researchers release their results to the community via some form of OA distribution model. According to the Registry of Open Access Repositories Mandatory Archiving Policies (ROARMAP), there are now 54 funding organizations mandating some form of OA publication as a condition of a grant award, with an additional 10 funders considering some form of mandate. Beyond funding mandates, some 163 institutional mandates are in place worldwide, with several dozen more sub-institutional mandates. Many “traditional” (i.e., subscription-based) publishers are moving beyond limited experimentation with different OA options to full implementation of hybrid models. The SHERPA/RoMEO site provides a list of more than 100 publishers who offer hybrid OA services along with details of those plans. These hybrid models allow for accommodation of papers from authors who are either required to publish OA as a condition of their funding, or due to adherence to an institutional mandate, or are simply choosing to pursue OA publication for their own personal preferences.

While there are an increasing number of OA articles in these hybrid titles, there is no standard way to represent to readers, or to discovery systems, that an article is freely available outside of a subscription wall. In most cases, discovery and link-resolution systems describe access terms only at the journal level, so OA papers that are published in hybrid journals might not be made visible to patrons because of the systems’ presumption about access. If a searcher does not specify they would like to include all indexed articles, all of the content contained within a subscription-based journal title that the institution does not have access to will likely be excluded from search results. If a user does specify they want a broader “all-content” search and is provided with an OA article as a result option, often the only way to determine if an article is freely accessible is to attempt to gain access and await the appearance or absence of a paywall.

Similarly, there is no standard logo or icon that is used to represent OA. The Public Library of Science and SPARC released for public use the “open lock” logo. The German openaccess.net project made another OA logo available, but neither logo has been broadly adopted as the standard indicator of OA content by publishers. For example, out of five publishers — Nature, Springer, Elsevier, Emerald, and the American Chemical Society — that provide some form of free access to journal content, each displays that fact quite differently on their internal tables of contents. Nature notes the article with orange “open” text beside the title of the article. Springer uses an orange “Open Access” tag in hybrid journal table of contents. Springer also uses a separate broken circle on its SpringerOpen brand, with a blue “OpenAccess” tag next to open article titles. Elsevier uses a green “key” logo on its journal lists to indicate a title has OA, but the key can mean all OA or hybrid. On the individual issue tables of contents, the full text “page” icon is green where an article is OA and white where it is not; a large button with the price on it makes it obvious where payment is required. Emerald notes with a check box what content one has available and at what level, i.e., abstract, backfile, etc. The American Chemical Society notes OA articles with a “Sponsored Access” badge. These are only a few examples of the wide diversity of approaches to this issue. Indications of open access status are as varied as there are opinions about OA’s value in the community.

More important than the visible OA indicator, however, is the back-end metadata, which will be shared with search engine providers, indexed search services, and aggregator services. There is currently no common article-level bibliographic metadata that provides information on whether a specific article is openly accessible. A few services do store some of this information, notably CCC and SIPX, but that information is not broadly distributed. Another challenge for indexing systems is that some content might be embargoed, where access is restricted for a period of time before becoming open access. Finally, while some content might be open for reading, it might not be sharable or reuse-able — and where some re-purposing is available, wide variations exist in what is and isn’t allowed. Currently, there is nothing in place that would allow machine understanding of these characteristics so that any automation can be applied. The use of a metadata structure could be a mechanism for addressing this and other discovery-related issues surrounding this hybrid mix of open- and subscribed-access systems.

Beyond simply accessing content there are several additional use cases for OA metadata at the article level. With an appropriate metadata system, discovery services could use such content-level information for improving their services. The NISO/UKSG KBART project has highlighted this situation in its recommendations for improving link resolver knowledge-bases. To provide users with information about re-use rights, and to be of computational use, this information is required to be in a machine-readable form. Funding organizations could potentially automate the assessment of compliance with their mandates. Institutions might also want to assess their own investments and resource allocations, and researchers might like to determine which journals are compliant with a given funder policy. Libraries are also interested in assessing the amount of OA content that is included within subscription titles, since many hybrid-OA publishers are willing to reduce subscription costs if take-up of author-pays models advance.

Developing such article-level metadata and public indicators are not without their challenges. First among them is the sheer scale of metadata management at the article level. Even at the title level, managing access information is no small feat and despite concerted efforts by several large discovery service providers and library systems suppliers, the title-level problem is only marginally solved. Publishers and libraries are still struggling with the expression of rights expression at the title or even the collection level. Expressing rights information is a complex problem, not least of all because rights documents are verbosely written in legalese and are very dependent on specific licenses, so that even a particular title (let alone an article) could have numerous variations in rights from one licensee to another. This is compounded by some publishers’ value propositions for obtaining revenue on re-use rights of content that is available for free reading. Finally, there are many competing marketing and branding interests tied to the association with certain agreed logos. Overcoming this final obstacle might be the simplest of the three problems, but consensus on many OA issues has often been hard fought and often hard to reach across all members of the scholarly community.

Regardless of a publisher’s particular stance regarding OA, communicating article-level access information is becoming an important factor in our community and one that publishers are going to have to face. Just providing OA options may not be sufficient to either authors, mandating institutions, libraries, or end users unless the OA indications are made clear not just to people, but also to machines that will index, describe, or assess the OA content. Publishers should aim to meet those authors’, funders’, and users’ needs by providing the fullest service possible and by taking advantage of the many benefits that OA provides if made visible to the community.  Certainly some are making efforts, but community consensus will allow tools and systems to take full advantage of the investments in OA. By improving the metadata and indicators of OA availability, along with information on re-use options, the improved discovery and end-user experience should yield higher usage and impact for these articles. And isn’t that the end result that everyone wants?