Source Databases
Description of Source Databases
The Journal Monitor (OAM-CH) uses journal article data collected from Unpaywall (which uses digital object identifiers (DOI) as a standard), enrich the data with data from Crossref (ISSN), mapped (via ISSN) against the Directory of Open Access Journals DOAJ (OA Model assigned to journal) and a static list of journals, and further enrich the data using DOI by institution ID (ROR) and corresponding status from the OpenAlex database.
- Unpaywall harvests Open Access content from publishers and repositories. In addition to articles, publication channels and licences are also recorded. This information is used in the monitor to calculate the OA proportions and to assign an OA model to each publication. Please see also OA typology.
- Crossref interlinks millions of items from a variety of content types, including journals. Linked content includes materials from Scientific, Technical and Medical (STM) and Social Sciences and Humanities (SSH) disciplines.
- Directory of Open Access Journals (DOAJ) is a freely accessible, independent database, which indexes peer-reviewed Open-access journals covering all areas of science, technology, medicine, social sciences, arts, and humanities. For each journal, in addition to various metadata such as publisher or LCC subjects, the database also includes the first year of OA and the amount of any APCs incurred.
- Research Organization Registry (ROR) is a freely accessible database that catalogues research institutions worldwide in a standardized format and provides them with persistent identifiers. It is a community-led project that includes other metadata such as relationships between organizations and other links. The names of cantons from ROR are standardized so that a uniform German, English or French spelling is used.
- OpenAlex is used as a source for publication references. All journal articles whose publication type is “article” are included in OA monitor analyses. The database contains information on the corresponding author.
Merging the Source Data
1. Unpaywall
- genre = “journal-article”
- is_paratext = false
In the first step, Unpaywall takes all publications that meet the following conditions:
Information taken from the Unpaywall data set:
- DOI
- journal(ISSNs)
- publisher
- OA model
- publication date
In addition, the publisher is labelled as Open Access using a stored list.
2. CrossRef list of titles
Next, the ISSNs provided by Unpaywall are looked up in the Crossref list of titles. All available ISSNs are considered and compared on an individual basis. If exactly one result is found, the respective journal is included.
After that, further information for the journal is added and mapping is carried out via ISSNs:
- DOAJ for the OA model assigned to the journal
- static lists of journals (mirror journals, OA publishers)
3. OpenAlex
The following information is taken from OpenAlex:
- institutions involved and corresponding status
The mapping between Unpaywall and OpenAlex is carried out via the DOI and is successful if exactly one publication is found for the DOI. ROR is taken as the standard data set for the institutions (which is supported by OpenAlex).
