Publication channels may be nominated by Norwegian academics, and the database does not accept self-nominations by publishers.
The database was started at the University of Oslo, but later became a national system operated on behalf of the government.
In 2010, Frida was transferred to the government and became a national research documentation system, and was renamed CRIStin.
Level 1 is the standard rating for publication channels considered to meet academic quality criteria, and is intended to cover at least 80% of all serious journals and publishers in a given discipline.
Level 2 is the highest rating and is reserved for the internationally[5] most prestigious journals and publishers within the discipline.
The "0" rating may imply that the publication channel lacks adequate peer review or that it in some other way doesn't meet basic quality standards for academic journals, that it is a trade journal with no academic aspirations or some other form of entirely non-academic publication, or that it is regarded as predatory.
Such publication channels are not systematically included in the index, and the rating may, but doesn't necessarily, indicate that the publication channel was nominated for "level 1" status and failed to be approved as such, or that it has been downgraded from "level 1" status, e.g. due to predatory publishing practices.
[7][8] Becoming operational in the autumn of 2021, the National Publication Committee linked the creation of level X to concerns regarding the publisher MDPI.
[16] The responsibility for the European Reference Index for the Humanities and the Social Sciences, now called ERIH PLUS, was transferred from the European Science Foundation to the Norwegian Centre for Research Data in 2014 and is now available on the same website as the Norwegian Scientific Index.