Subject classification update: a stricter confidence rule and a Multidisciplinary group
Subject categories are computed from each journal’s OpenAlex topics. Long-established general journals carry topics from many fields, and under the previous rule some of them were assigned to a single category with high confidence, which placed them in that category’s ranking.
Under PSC-CROSSWALK-0.3, a high-confidence assignment requires the leading category to hold at least 35% of the journal’s topic mass and at least 1.5 times the next category. Journals where no category or domain dominates are listed as Multidisciplinary. They are ranked across all journals but not within a subject category.
The 2026 ranking edition has been recalculated under the new rule. Overall ranks are unchanged; 2,963 journals now hold a category rank. The rule is described in the methodology.