Advance online publication
- How often are new articles published AOP?
- Do the Nature Research Journals use AOP for front-end matter?
- Can the AOP version of the article be considered definitive?
- What is a digital object identifier?
- What do the numbers in the DOI signify?
- What is CrossRef?
- Where does the DOI appear?
- How can I use a DOI to find a paper?
- How can I recognize whether a copy of a paper is the AOP version or the volume/issue/page (often called 'print') version?
- What are the page numbers that appear in PDFs of AOP papers?
- What is the 'official' publication date?
- What determines the order in which AOP papers are listed on the website?
- How do I cite a paper that is an AOP but is not in print?
- Does Medline use DOIs?
- Does The Institute for Scientific Information use DOIs?
- How does AOP affect the calculation of impact factors?
- How does AOP affect press releases and embargoes?
- Must I subscribe to the journal in order to read AOP articles?
All monthly Nature Research Journals offer Advance Online Publication (AOP) on their websites.
Each journal's website includes an AOP table of contents, in which papers are listed in order of publication date (beginning with the most recent). Each paper carries a digital object identifier (DOI), which serves as a unique electronic identification tag for that paper. As soon as the monthly issue is printed, papers will be removed from the AOP table of contents, assigned a page number and transferred to that issue's table of contents on the website. The DOI remains attached to the paper to provide a persistent identifier.
We believe that rapid online publication is a valuable service to both readers and contributors, and we encourage you to visit our sites often.
Top of pageFrequently asked questions
Q How often are new articles published AOP?
A New articles are uploaded to the AOP section of our website once per week, on Sundays. Occasionally, an article may be fast-tracked and uploaded on other days, but this is reserved for articles whose publication is considered exceptionally urgent.
Q Do the Nature Research Journals use AOP for front-end matter?
A Most front-end items (news, News and Views, editorials,and so on) are published only once per month, online and in print. Occasional News and Views are published with their accompanying research papers in the AOP section.
Q Can the AOP version of the article be considered definitive?
A Yes. Different publishers have different policies, and some journals choose to publish unedited versions of articles on their websites. Our policy, however, is to publish only the final edited version of the paper. The paper is thus complete in every respect except that instead of having a volume/issue/page number as an identifier, it has a DOI (digital object identifier).
Q What is a digital object identifier?
A A digital object identifier (DOI) is an identifier string (combination of numbers and letters) that can be assigned to an item of editorial content and that provides a unique identifier for that item. The DOI system is administered by the International DOI Foundation, a not-for-profit organization, with the aim of providing a common format for cross-linking of electronic content from different publishers. The lookup system for DOIs is maintained by CrossRef, a not-for-profit organization whose aim is to enable the ongoing usage of DOI as a reference linking standard. The Nature Publishing Group is a founding member and board member of CrossRef.
Q What do the numbers in the DOI signify?
A The DOI has two components, a prefix (before the slash) and a suffix (after the slash). The prefix is composed of a DOI resolver server identifer (10) and a unique identifier assigned to a particular publisher - for example, the identifier for the Nature Publishing Group is 1038. Therefore the entire DOI prefix for an article published by the Nature Publishing Group is 10.1038. The suffix is an arbitrary number provided by the publisher. It can be composed of numbers and/or letters. It does not necessarily have any systematic significance - for instance, it does not automatically indicate the page number or the date of publication. Each DOI is registered in a central resolution database that associates it with one or more corresponding web locations (URLs). For example, the DOI 10.1038/ng571 connects to http://dx.doi.org/10.1038/ng571.
Q What is CrossRef?
A CrossRef is a not-for-profit organization that develops and maintains a system to assist in the linking of published papers based on their DOIs.
Q Where does the DOI appear?
A For articles appearing in the Nature Research Journals, the DOI appears in the print version beneath the affiliations, on the first page.
Q How can I use a DOI to find a paper?
A There are two ways to use a DOI to find a paper:
- DOIs from other articles can be embedded into the linking coding of an article's reference section. In Nature journals these appear as "|Article|" in the reference sections. When |Article| is clicked it opens another browser window and takes you to the entrance page (often the abstract) for another article. Depending on the source of the article, this page can be on the Nature Publishing Group site or a site of another publisher. This service is enabled by CrossRef.
- If you know a DOI, you can insert it directly into your browser's location bar as follows. For the DOI 10.1038/ng571, you would type: http://dx.doi.org/10.1038/ng571. This will bring you to the entrance page of the desired article.
The material found on the entrance page (bibliographic data or abstract) is free to everyone. On that page, you will also find a link to the full text for that article. Clicking on that link will give you either the full text (for institutional subscribers) or a user login page, from which you can access the full-text article by entering your userID and password. For users who are not subscribers and who do not have a userID and password, many publishers offer document delivery from their websites.
Q How can I recognize whether a copy of a paper is the AOP version or the volume/issue/page (often called 'print') version?
A The AOP version (which can be viewed in HTML or PDF format) is identical to the final online version in every respect regarding content and presentation, except that instead of having a volume/issue/page number it has only the DOI as an identifier. It can be identified, however, by looking at the footer within the PDF file, which states "Advance Online Publication."
Q What are the page numbers that appear in PDFs of AOP papers?
A For convenience, the PDF version of every AOP article is given a temporary pagination, beginning with page 1. This is unrelated to the final pagination of the printed article.
Q What is the 'official' publication date?
A Many journals, and most abstracting and indexing services (including Medline and Institute for Scientific Information) still cite the print date as the publication date. This is an evolving standard, however, and the trend now is for publishers to state both the 'Online Publication Date' and the 'Print Publication Date'. The Nature Publishing Group will continue to publish both dates for our own papers, and we hope that the scientific communities and abstracting and indexing services will recognize these dates.
For the time being, the reference lists of our papers will continue to follow the standard convention of citing by print publication date. Thus, there will be no immediate change to the reference format instructions in our Guides to Authors (but see below for how to cite papers that have not yet appeared in print). We expect, however, to review this policy regularly as community standards evolve.
For legal purposes (for example, establishing intellectual property rights), it is our assumption that online publication will constitute public disclosure. This is, however, for the courts to decide; our role as a publisher is to provide clear documentation of the publication history, online and in print.
Q What determines the order in which AOP papers are listed on the website?
A AOP papers within a given section (Articles, Brief Communications, etc.) are listed in order of online publication date, most recent first. Papers published on the same date are listed alphabetically by first author. Thus, the order of AOP listing does not necessarily correspond to the order of subsequent print publication.
Q How do I cite a paper that is an AOP but is not in print?
A One advantage of the DOI system is that papers can be cited using a DOI only, before final pagination and print publication. The DOI is a persistent identifier, which remains with the article even after it is published in print. We recommend citing DOIs as follows: At the end of the reference citation, type the complete DOI (for example, doi: 10.1038/ng571).
Q Does Medline use DOIs?
A Medline currently captures DOIs along with online publication dates in its records and is working on enhancing its level of support for the DOI system.
Q Does The Institute for Scientific Information use DOIs?
A The Institute for Scientific Information (ISI) currently captures DOIs in their records. However, the DOI is recorded at the same time as the volume/issue/page number. Therefore, it is not using the DOI to capture information prior to print publication, but rather recording it simply as an additional piece of metadata to complete its records.
Q How does AOP affect the calculation of impact factors?
A Impact factors are calculated by ISI. At present, ISI bases its calculations on the date of print publication alone. It is possible that the ISI will choose to change this policy in the future, but under the present system, AOP has no effect on impact factor calculations.
For a full explanation of how impact factors are calculated, see: http://www.isinet.com/essays/journalcitationreports/7.html
Q How does AOP affect Press releases and embargoes?
A The Nature Research Journals will distribute a joint press release every Tuesday, to alert journalists to articles that are scheduled for AOP the following Sunday. The embargo on those papers is lifted at 13:00 US Eastern time, the day of online publication. If you are a member of the press and would like to receive these weekly Press releases, please contact our press office at press@nature.com.
Q Must I subscribe to the journal in order to read AOP articles?
A Yes. While abstracts are freely available to anyone on our website, access to the full-text article requires a paid subscription or a site licence.