The following glossary lists and briefly explains basic open-access-related terms used on the website

An overview of all terms can be found at the end of this page.


Altmetrics are bibliometric indicators that measure a scholarly publication’s im­pact. They capture the diverse reactions that a publication may receive on the Web, and have established themselves as an extended alternative to the tradi­tional bibliometric measures, such as the Journal Impact Factor. The data are generated automatically, and relate, for example, to the number of downloads and links and to mentions, discussions, and likes in social media or blogs. → Impact Factor


APCs (article processing charges) are publication fees charged by open access journals. Only around 30 % of all open access journals charge APCs. As a rule, APCs are payable to the publisher by the author(s) or their institution/employer after the article has undergone peer review and been accepted for publication. → Peer review Publication charges


arXiv (pronounced archive) is a document server for → preprints in the fields of physics, mathematics, computer science, and related domains. Founded in 1991 by Paul Ginsparg at Los Alamos National Laboratory to make preprints in physics freely available, it is now maintained and operated by Cornell University.


BASE (Bielefeld Academic Search Engine) is one of the largest search engines for academic Web documents in the world. It accesses, inter alia, texts in → repositories. The majority of documents indexed in BASE are freely available in full-text form (→ open access). BASE is operated by Bielefeld University Library.

Berlin Declaration on Open Access to Knowledge in the Sciences and Humanities

By signing the Berlin Declaration to Knowledge in the Sciences and Humani­ties, research organisations and universities commit to supporting the further development of the idea of open access, for example, by encouraging resear­chers to publish their results in an open access journal or to make them avail­able in an open access repository.→ Bethesda Statement on Open Access PublishingBudapest Open Access Initiative

Bethesda Statement on Open Access Publishing

The Bethesda Statement on Open Access Publishing stresses the need to dis­seminate the results of scientific research quickly, efficiently and according to the principles of open access. It emphasises the opportunity and the obligation to share research results, ideas and discoveries freely with the scientific com­munity and the public. → Berlin Declaration on Open Access to Knowledge in the Sciences and HumanitiesBudapest Open Access Initiative


The concept of bibliodiversity, which describes the diversity of book culture, probably arose in Latin America in the 1990s. It was applied to open access in the Jussieu Call for Open science and bibliodiversity, which was drafted in 2017 by a group of French researchers and scientific publishing professionals. The Call stated that: "Open Access must be complemented by support for the diversity of those acting in scientific publishing – what we call bibliodiversity – putting an end to the dominance of a small number among us imposing their terms to scientific communities." Scholar-led publishing


The German Federal Ministry of Education and Research (BMBF) supports innovative research projects and ideas through targeted funding programmes. It supports → open access also as a fundamental funding principle, and wants to increase the visibility and acceptance of this principle. The funding initiatives are part of an Open Access Strategy adopted by the BMBF in 2016.


BPCs (book processing charges) are publication fees that publishers charge authors for the publication of scholarly books in → open access. These charges are often borne by the institutions at which the authors are employed or by a funding agency. → Publication fundsPublication charges

Budapest Open Access Initiative

The Budapest Open Access Initiative (BOAI) is a coalition of international scholars and scientists. In a Declaration published in 2002, the initiative called for free and unrestricted access to, and reusability of, scholarly literature in all academic fields. → Berlin Declaration on Open Access to Knowledge in the Sciences and HumanitiesBethesda Statement on Open Access PublishingOpen Access

Closed Access

Closed access, also known as toll access, is the opposite of → open access. It means that access to publications is possible only for a fee.

cOAlition S

The international consortium cOAlition S comprises a large number of national research funding organisations; it is supported by the European Commission. The consortium developed Plan S, an initiative for the implementation of → open access to publications resulting from funded research projects. → Plan S

Creative Commons licences

The non-profit organisation Creative Commons has made several copyright licences, known as Creative Commons licences, freely available to the public for use. The licences are widely used and easily understandable. They also offer a high degree of flexibility by virtue of the fact that they can be assembled from four combinable licence elements:

  • BY – Attribution: The name of the creator must be provided and where technically possible a link to the original material and the CC license.
  • ND – No Derivatives: The work may be modified, but the modified version may not be distributed.
  • SA – Share Alike: The work may be modified, but the modified version may be distributed only under the same licence as the original.
  • NC –Non-Commercial: The material may be used only for non-commercial purposes.
  • Licence


Projekt DEAL was initiated by the German Rectors’ Conference on behalf of the Alliance of German Science Organisations. The aim of Projekt DEAL is to conclude nationwide publish and read agreements (licence agreements with an → open access component) with the largest scholarly publishers (Elsevier, Springer Nature, and Wiley) for the entire portfolio of e-journals. An agreement was concluded with Wiley in 2019 and with Springer Nature in 2020. → Transformation


The German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) is the self-governing organisation for science and research in Germany and the largest national research funding agency in Europe. Its members are research-intensive universities, non-university research institutions, scientific associa­tions, and the academies of science and the humanities. The DFG promotes → open access with various national and international programmes.

Diamond Open Access

Many open access journals function without → article processing charges (APCs) – that is, no costs arise for authors, but rather the journal is financed from institutional funds, by funding agencies or, for example, by library consortia in which various libraries come together. This model, which is also known as platinum open access, is a variant of → gold open access. → open access


The Deutsche Initiative für Netzwerkinformation (German Initiative for Net­work Information, DINI) promotes inter alia the development of Web standards to ensure that → open access literature in → repositories is findable, archived on a long-term basis, and accessible.

DINI Certificate

The DINI Certificate for → Open Access Publication Services is a recognised quality seal for → repositories that makes the quality of the services provided clearly recognisable to authors, users, and funders. Repository operators can apply to DINI for certification. → DINI


The Directory of Open Access Books (DOAB) is a searchable index of academic → peer-reviewed books published in → open access. It offers links to the full texts of these publications on publishers’ websites or in → repositories.


The Directory of Open Access Journals (DOAJ) is a community-curated online directory of open access journals founded at Lund University. The DOAJ is provided by an independent non-profit organisation of the same name. To be included in the directory, journals must fulfil a number of criteria, for example, appropriate quality control procedures and immediate → open access without an → embargo period.


A Digital Object Identifier (DOI) is a persistent identifier that comprises alpha-numeric characters. This identifier refers to a dataset or a digital object that can be retrieved via these identification digits. With the help of a DOI, a text or data publication can be permanently cited.


The San Francisco Declaration on Research Assessment (DORA) calls for an improvement in the ways in which the outputs of scholarly research are evaluated. The declaration has given rise to a worldwide initiative in which all scholarly disciplines and all key stakeholders are represented. DORA criticises inter alia the misuse of the Journal Impact Factor to evaluate scholarly research outputs. → Impact Factor

Double Dipping

The term double dipping refers to a phenomenon where publishers of subscrip­tion journals charge authors additional high fees to make individual articles available in open access. Thus, the publishers obtain revenue from two sources at the same time: from journal subscriptions and from the additional open access charges. This publication model is also known as hybrid open access: in contrast to "genuine" open access, the entire journal is not freely accessible, but rather authors pay article processing charges (APCs) to "buy" the freedom of individual articles. → Hybrid journals Open access Subscription

Dual Publishing

Dual publishing refers to the parallel publication of a digital → open access version and a fee-based print version of a work. It is frequently observed in the area of open access book publishing.

Embargo Period

An embargo period is a time delay after which publishers allow authors to make the full texts of their publications available to the public in a → repository (in the sense of → green open access). The length of the embargo period is at the discretion of the respective publishers. In the case of journals, it is usually between 6 and 12 months, and sometimes even 24 months. → Self-archiving

Fair Open Access

Fair open access is a non-profit version of gold open access. It strives for full, immediate and transparent implementation of open access. At the same time, it aims to return control over the publication process to the scholarly community. These principles are supported by the Fair Open Access Alliance (FOAA). → Gold open accessScholar-led publishing


The Austrian Science Fund (FWF) is Austria’s central funding organisation for basic research. The FWF supports → open access to scholarly publications and research data, and requires scholars and scientists to make research outputs that result from FWF-funded projects freely available on the Internet. The FWF is a member of → cOAlition S.


HAL (Hyper Articles en Ligne) is the central → open access repository in France. It is operated by the French research organisation Centre national de la recherche scientifique (CNRS).

Hybrid Journals

Hybrid journals are subscription-based journals that offer their authors the option of "buying the freedom" of individual articles (i.e., making them → open access immediately on publication) by paying an article processing charge (APC). Hybrid publishing involves a risk of double dipping, whereby an article is paid for twice – through journal subscriptions and the APC → APCClosed accessDouble dipping → Mirror journalSubscription

Impact Factor

The Journal Impact Factor is a numeric measure of the average number of cita­tions of the articles published in a given journal in the past two years. It is used for the purpose of bibliometric comparison and often also as an indicator for the quality of a journal and the articles that appear in it. The Impact Factor is calculated on the basis of the journals covered by the Science Citation Index; it thus also covers open access journals. There is growing criticism of the misuse of the Impact Factor to evaluate outputs of scholarly research. → DORA

Information budget

The information budget of a scientific institution comprises all funds for the literature and information supply and for publication costs (adapted from: Glossary, p. 96, Recommendations of the Transformation of Academic Publishing Towards Open Access, 2022. German Science and Humanities Council. Open Access Monitor   Publication funds   Transformation

Knowledge Unlatched

The Berlin-based commercial → open access service provider Knowledge Unlatched offers possibilities for financing open access publications through a crowdfunding model.


Licences are standardised agreements by means of which the rightholder grants rights of use in a work to a third party. A licensing model meets the requirements of → open access when it allows free worldwide access to, and unrestricted reuse of, a publication. The most widely used open licences in the area of science and research are the Creative Commons licences (CC licences). → Creative Commons licences

Mirror Journal

So-called "mirror journals" were founded by some major publishers to circumvent the exclusion of funding for OA publication fees in hybrid journals. These are OA versions of subscription journals whose subject focus and editorial boards are largely identical to those of the corresponding subscription journal. → APCHybrid journalsPlan SSubscription


Open Access 2020 (OA2020) is a global alliance of science and research organisations initiated by the Max Planck Digital Library. It is committed to accelerating the transition from the current → subscription-based scholarly publishing system to → open access publishing models. The aim is to ensure that research articles are immediately available in open access as soon as they are published, and that the costs behind their dissemination are transparent, fair, and economically sustainable. → Transformation


The Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH) is a metadata exchange protocol for → repository interoperability. Repositories (data providers) expose their structured metadata via OAI-PMH. These metadata can then be harvested by service providers via OAI-PMH service requests.

Open Access

The → Budapest Open Access Initiative defines → open access as follows: "By open access to this literature, we mean its free availability on the public inter­net, permitting any users to read, download, copy, distribute, print, search, or link to the full texts of these articles, crawl them for indexing, pass them as data to software, or use them for any other lawful purpose, without financial, legal, or technical barriers other than those inseparable from gaining access to the internet itself. The only constraint on reproduction and distribution, and the only role for copyright in this domain, should be to give authors control over the integrity of their work and the right to be properly acknowledged and cited." → Gold open accessGreen open access

Gold Open Access

Gold open access refers to the publication of scholarly works as articles in open access journals, as open access monographs, or as contributions to open access collections or conference proceedings. As a rule, these texts undergo the same quality assurance process as → closed access works, mostly in the form of → peer review or editorial review. → Open Access

Green Open Access

Green open access – also known as self-archiving – refers to making works published with a publisher or in a journal available to the public in a repository. It is sometimes understood to refer also to making such works available on the author’s personal website. Self-archiving can take place at the same time as the publication of the content by the publisher or at a later date, and is possible for preprints and post-prints of scholarly articles, as well as for other document types, for example, monographs, research reports, and conference procee­dings. → Open accessRepositoryPreprint Post-printSelf-archiving

Open Access Monitor

The Open Access Monitor collects data on the publication output of academic institutions in Germany, analyses subscription and publication expenditure and citations, and statistically processes the data. It is operated by Forschungszen­trum Jülich. → Subscription

Open Access Policy

In an open access policy or open access guidelines, organisations specify their guidelines in relation to → open access. These guidelines determine the roles, rights and obligations of various actors within the institution with regard to the implementation of open access.


Open Access Infrastructure for Research in Europe (Open AIRE) is a European-Commission-funded project that was launched in 2009 with the aim of establi­shing an electronic infrastructure to archive research publications from all 27 EU member states, to handle articles, → preprints, and conference publications, and to manage research datasets.


Open Journal Systems

Open Journal Systems (OJS) is the most widely used open source software application for managing manuscript submissions and peer review and for publishing scholarly journals. → Peer review Public Knowledge Project

Open Monograph Press

Open Monograph Press (OMP) is an open source software for managing and publishing scholarly books. It can be used to manage the editorial workflow required to publish monographs, edited volumes, and scholarly editions. → Public Knowledge Project

Open Peer Review

Open peer review refers to variants of the quality control of scholarly manuscripts that, in contrast to traditional peer review, take place in a transparent, open, and sometimes also collaborative way.→ Peer Review


In general terms, to opt out means to choose not to – or no longer to – avail, for example, of a service or an option by making an opt-out declaration. Research funders that mandate → open access or open data sometimes offer an opt-out option – that is, the possibility of deciding for legitimate reasons against making research outputs freely available to the public (for example, when this is not compatible with the protection of personal data).

Overlay Journal

Overlay journals are open access journals that use the infrastructure of preprint servers. For example, authors make the preprints of their manuscripts freely available in arXiv and at the same time submit them for publication to an overlay journal. If the submitted article successfully undergoes peer review and is accepted for publication, the original version continues to remain available alongside the edited publisher’s version. → arXivPeer reviewPreprint

Peer Review

Peer review is the most widely used procedure for controlling the quality of scholarly contributions before their publication. It involves the evaluation of a scholarly work by independent reviewers who are experts in the same field (hence peer, as in "belonging to the same group") → Open Peer Review

Plan S

Plan S is a strategy initiated by an international consortium of research funding organisations – cOAlition S – with the aim of implementing immediate → open access to scholarly publications resulting from funded research projects. Under this plan, recipients of funding from member organisations of cOAlition S will be required to make publications resulting from funded research available in open access by publishing them in high-quality open access journals or on high-quality open access platforms, or by making them immediately available with­out embargo in open access repositories that fulfil the necessary requirements. → cOAlition S


A post-print is a scholarly text that has already undergone peer-review and has been accepted for publication. There are two types of post-prints: on the one hand, a post-print may be completely identical to the final published version, also known as the publisher's version or the version of record. On the other hand, the post-print may be substantively the same as the publisher’s version but differ, for example, in terms of formatting, layout, or pagination. In the latter case, it is known as the author’s accepted manuscript (AAM). → Version of record

Predatory Publishing

Predatory Journals are journals that use aggressive advertising and a seemingly professional appearance to lure scholarly authors into publishing contributions against payment of a → publication fee, but that do not provide any – or provide only inadequate – quality assurance measures.


A preprint is a scholarly work that has not (yet) undergone peer review. The term is sometimes also used to refer to the manuscript version of a work that is submitted for publication to a journal or a publisher. → Peer review

Public Knowledge Project

The Public Knowledge Project (PKP) is a research and development initiative within the framework of which open source software applications for managing and publishing scholarly journals and conferences was developed. These applications – Open Journal Systems (OJS), Open Conference Systems (OCS), and Open Monograph Press (OMP) – improve access to knowledge and help to reduce publishing costs. → Open Journal Systems Open Monograph Press

Publication funds

Open access publication funds are an instrument through which scientific and scholarly institutions support their authors in paying open access publication charges. This often involves reimbursing article processing charges (APCs) or book processing charges (BPCs). However, it may also entail funding consortial offerings, open access infrastructures, or the  transformation of subscrip­tion journals into open access journals. In this way, scientific and scholarly organisation contribute to financially supporting open access publications. In this pursuit, they are usually guided their own criteria for the reimbursement of the costs incurred. APCBPCPublication charges

Publication charges

Publication charges are fees charged by publishers prior to publication. For example, some publishers charge for colour figures (colour charges) or for the number of pages in a publication (page charges).  In the open access context, publication charges are a possible business model for financing the publication. Because open access publications are always free to use for readers, the publication is paid for not by the readers but by the publishing authors. The fees charged for the publication of an article are known as article processing charges (APCs), while the fees for the publication of a book are called book processing charges (BPCs). → APC BPC

Publish and Read

“Publish and Read” is a contract component to finance scholarly journals that is often used in transformative agreements between library consortia and publishers. The publish and read agreements negotiated by Projekt DEAL are a well-known example. In this type of financing, the participating research institutions pay not only to read the content of the journal in question (as is the case with subscriptions) but also for their authors to publish open access in that journal. Reading access is covered by the publish and read fees. The level of the fees is calculated based on the publication output of the individual institutions. → DEAL Subskription Transformation


A repository is a document server at a university or a research institution on which scholarly materials are archived and made available to the public worldwide on a long-term basis. Two types of repositories are distinguished: institutional repositories (operated by insitutions such as university libraries, other infrastructure organisations, or research organisations) and disciplinary repositories (trans-institutional, thematically bundled, e.g., for a particular discipline). → ROAR


In traditionellen Verlagsverträgen übertragen Autor*innen oft einen erheblichen Teil ihrer Rechte an Verlage, was ihre Kontrolle über ihre eigenen Werke einschränken und dazu führen kann, dass sie nur eingeschränkte Möglichkeiten zur Verbreitung und Wiederverwendung ihrer eigenen Werke haben. Wissenschaftliche Einrichtungen können dem durch sog. “Rights Retention Strategies" entgegenwirken, z. B. indem sie mit ihren Wissenschaftler*innen Verträge abschließen, die den Einrichtungen das Recht zur Nachnutzung oder Zweitveröffentlichung wissenschaftlicher Werke einräumt – beispielsweise um sie in institutionellen Repositorien zu veröffentlichen, in Bildungsmaterialien einzubetten u. v. m. Eine Rights-Retention-Strategie kann Teil einer umfassenderen Open-Science-Strategie sein und hilft Einrichtungen wie Autor*innen, ihre Werke im Open Access langfristig sichtbar und zugänglich zu halten, ohne von Verlagsvereinbarungen eingeschränkt zu werden. → Repositorium


The Registry of Open Access Repositories (ROAR) is a list of open access repositories. The searchable international database indexes the establishment, location, and growth of institutional open access repositories and their content. → Repository

Scholar-led publishing

The term scholar-led publishing refers to a publication model where scholars organise and come together to publish their research results independently. Thus, scholar-led publishers are publishers led by scholars. → Bibliodiversity Fair open access


Self-archiving refers to making documents that have been published with a publisher or in a journal freely available to the public on open access document servers or repositories. When doing so, the legal conditions and the publishers’ conditions (e.g., embargo periods) must be observed. The term self-archiving sometimes also refers to making publications freely available on the author’s personal website. → Green open access RepositorySelf-archivingSecondary publication right

Sherpa Romeo

Sherpa Romeo (Rights Metadata for Open Archiving) is an online resource that aggregates and presents publisher and journal open access archiving policies. → Green open accessSelf-archiving


Mandated by the Swiss Federal Government, the Swiss National Science Foundation (SNSF) supports research in all academic disciplines. Moreover, grantees are required to make the results of SNSF-funded research available in an open access publication or repository.

SPARC Europe

The Scholarly Publishing and Academic Resources Coalition Europe (SPARC) is an alliance of European scholarly and research libraries, national libraries, library organisations, and research institutions. It aims to advance the open access movement.


The Social Science Research Network (SSRN) is one of the largest preprint servers in the social sciences. The searchable database offers researchers the opportunity to upload working papers and abstracts free of charge. After SSRN was taken over by the major publisher Elsevier in 2016, the announcement to found the non-profit server SocArXiv for preprints in the social sciences followed shortly afterwards. → Preprint


Traditionally, journals have been funded via subscriptions: publishers publish journals to which interested users subscribe in order to obtain access to the content. In the scholarly context, subscribers are mostly the libraries of scholarly institutions. Rising journal subscription prices in the 1990s led to what became known as the serials crisis. A counter-model to subscription is open access. → Open accessSerials crisis


In the context of open access, the term transformation refers to the complete conversion of the scholarly publication system to open access, inter alia by converting traditional subscription journals into open access journals.  → OA2020Gold open accessPlan SSubscription

Version of record

The version of record, or publisher’s version, is the version of a text that has already undergone peer review and been accepted for publication. It is identical with the formally published version of the work (i.e., the version published with a publisher or in a journal). → Post-print

Serials crisis

Rising journal subscription prices in the 1990s led to what became known as the serials crisis. While journal prices continue to increase, libraries have only a cer­tain budget for the purchase of journals. Due to the higher costs, they are obliged to cancel journal subscriptions. It therefore becomes increasingly difficult to adequately supply scholars and scientists with the scholarly information they require. → Subscription


Zenodo is an all-purpose open access repository that was developed within the framework of the European OpenAIRE project; it is managed by CERN. Zenodo enables researchers to make datasets, research software, reports, and other research-related digital documents available to the public. A persistent Digital Object Identifier (DOI) is issued for each submission, thereby facilitating the citation of the stored objects.


Secondary publication right

The secondary publication right is a limitation under German copyright law that gives the author of a contribution to a periodically published collection the right to make the contribution available to the public online – for example by self-archiving it in a → repository after an → embargo period of 12 months, even if the publisher has already been granted an exclusive right of use. The prerequisite is that the contribution was produced in the context of publicly funded research. The secondary publication right refers to the accepted manuscript version of the contribution (i.e. the author's final version of the work, as accepted for publication following peer review but without the publisher's layout). The author is not obliged to make use of the secondary publication right. The contribution may not be made available under an open → licence (see Section 38 of the German Act on Copyright and Related Rights (UrhG)). → Post-print