2.2 Green and Gold Open Access
The terms green and gold were coined in 2004. However authors were already providing content by these means much before but the explicit distinction was made by Harnad et al. (2004) that defines Green Open access as: "mode of publishing in non open access journal but also self archiving it in an Open Access archive"What it means is that “the author can self-archive at the time of submission of the publication (taking the 'green' route) whether the publication is grey literature (usually internal non-peer-reviewed), a peer-reviewed journal publication (with required permissions), a peer-reviewed conference proceedings(with required permissions) paper or a monograph”.Usually green OA publishing includes articles such as preprints that precede formally published versions. the advantage for end users is that the preprints maybe a near enough version of final formally published article and would suffice for their reference without having to pay heavy prices to acquire or access the published version (Bjork et al., 2008). In green OA, the main types are institutional repositories and disciplinary repositories. Institutions often offer incentives and assistance for deposit, and to adopt policies to ensure deposit. A growing number of universities have policies to encourage deposits into university repositories. On the other hand, scholars who regularly refer to research in a large disciplinary repository, such as arXiv for physics or PubMedCentral for medicine, readily grasp the rationale for depositing their work in OA repositories (Harnad et al., 2004).
'Gold' route to open access aims to make articles and information resources open for access by publishing in a journal that is open access journal or an open access publisher. For example, Public Library of Science publishes only in open access mode (Harnad, 2004). There is no embargo period before an article is openly accessible. An open access journal may charge authors for making their articles as open access content but it is not true of all Gold OA publishers. Also the authors' parent institution or organization and even funding agencies may support the costs in open access publishing. Hence it means that “the author or author institution can pay a fee to the publisher at publication time, the publisher thereafter makes the material available 'free' at the point of access (the 'gold' route). The two are not, of course, incompatible and can co-exist”.
Broadly speaking self archiving as in greenopen access is mainly through OA repositories and publishing in OA journals or goldroute is considered to be through Open access journals that have publication workflows including peer reviews. Gold and green OA differ in two fundamental respects (Suber, 2012). “First, OA journals and repositories differ in relation to peer reviewing. OA journals perform their own peer review, just like conventional journals. Repositories generally do not go for peer review, although they may host and disseminate peer-reviewed” articles from other sources. While this is not true for all repositories it is still true for most of them. Due to costs involved in publication cycle gold and green OA differ in their support costs. Second, OA journals obtain the rights or permissions they need directly from the rights holders, while repositories ask depositors to obtain the needed rights or permissions on their own. Even when the depositors are the authors themselves, they may already have transferred key rights to publishers and in such cases may only deposit a pre-print of the article. Sometimes the author have even given undertaking that article published with commercial publishers will not be in any form, including drafts and pre-prints be deposited in any repository and not even on their own websites! Anyway leaving this apart, it is true that OA journals can generate permissions for reuse at will, and OA repositories generally cannot (Suber, 2012).
2.2.2 Advantages and Disadvantages
Green and gold OA are basically complementary and synergistic, the binding factor is that they both stem out from the same thoughts of OA and implemented by and for academic and research purpose upholding the basic philosophy of OA. Green and gold have different supporters from the community of open access advocates and activists. Some of them rank green higher than gold and yet others believe in the vice-versa. Green OA has some advantages over gold OA as the publication cycle can be very short as the wait for peer review process is absent. The OA journals however are dependent upon time and intellect of scholars performing reviewing. For the same reason green OA is deemed to be less expensive than gold OA, though there is an argument, that is largely true, that peers are not paid to review and ensure quality of content and even if they are paid it is only a very nominal token. Further green OA model can scale up quickly and inexpensively to meet demands of growing contents as most are based on Open source software. Another argument in favour of Green OA is that it can be mandated without infringing academic freedom, but gold OA cannot (Suber, 2012). From an institutional repository point of view, green OA enables institutes to completely record their research output while in gold OA it is up to the authors what they are willing to, or allowed to deposit. Further, green OA may host preprints as well as post prints while gold OA is only for post prints. Another advantage of green is that they can host a variety of resources such as theses and dissertations, datasets, multimedia such as video lectures, artifacts while gold OA is about formally publishing research articles only.
One of most significant advantages is that green OA models are naturally amenable to providing metadata in the resource acquisition workflow itself. The advantages of having detailed metadata that too from authors (or depositors themselves) cannot be over-emphasized. Also most of these are OAI-PMH complaint which is a worldwide standard for interoperability of digital repositories. Some OA journals predate the OAI PMH standard and hence are not compliant. Others do not run on platforms such as OJS that is naturally complaint with OAI. Hence OAI-PMH compliance may be an issue with gold published content. Gold OA has its advantages on certain counts (Suber, 2012). Gold OA is immediate, that is immediately after receiving a payment from the author or institution the resource could be made open access with no embargo period restrictions. The other advantage is that since peer review is seen as important bench mark of quality which is true of Gold OA. OA journals normally enlist experts in respective domains as reviewers to ensure quality. They have the required workflows between the system, reviewers, editors and authors to take care of the entire process. Sustenance is a major concern in Open access. The end users do not have to pay for accessing content. Though OA is meant to provide free access, the setup to provide OA is not free. It entails some expense. Then the questions arises how to sustain the whole process. Here gold OA scores higher than green, as OA journals can show income by charging for publishing.