August 13, 2022
CiNii is a bibliographic database service for material in Japanese academic libraries, mainly focused on Japanese works and English works published in Japan. The database was established in April 2005 and is maintained by Japan's National Institute of Informatics (NII). The service searches from the databases maintained by the NII itself (the NII Electronic Library Service (NII-ELS) and the Citation Database for Japanese Publications (CJP) respectively), as well as the databases provided by the National Diet Library of Japan , institutional repositories and other organizations. The database contains more than 22 million articles from more than 3,600 publications dating back to 1906. Tens of millions of searches are performed each month by several millions of unique visitors. CiNii is the largest and most comprehensive database of its kind in Japan. Although the database is multidisciplinary, most of the questions it receives are in the humanities and social sciences, perhaps because CiNii is the only database that includes Japanese scientific works in this field (as opposed to the natural, formal and medical sciences in which scientific domains can also fall back on other databases). CiNii provides access to three separate databases CiNii Articles, CiNii Books and (since 2015) CiNii Dissertations. Within these databases, unique identifiers are used for the publications from each catalog. The database assigns a unique identifier, NII Article ID (NAID), to each journal article and dissertation. Another identifier, NII Citation ID (NCID) is used for books. The database service also makes it possible to integrate the bibliographic activities and information services of Japanese academic production into international programs. The CiNii classification has acquired supranational importance and is used internationally.