Abstract

This study aimed to measure the multidisciplinarity and interdisciplinarity of journals in the Interdisciplinary Research category of the Korea Citation Index (KCI) and analyze their relationships with journal citations. By analyzing 74 journals and using entropy to measure the diversity of referenced and citing fields, several key findings were observed. First, journals in the KCI Interdisciplinary Research category exhibited higher multidisciplinarity compared to general fields, but showed no significant difference in interdisciplinarity. Second, there was a weak correlation between a journal’s multidisciplinarity and interdisciplinarity, and top-ranked journals in these areas did not overlap. Third, a journal’s multidisciplinarity was not related to its citation impact, while interdisciplinarity showed a strong correlation with citation impact. Fourth, both multidisciplinarity and interdisciplinarity significantly correlated with multidisciplinary impact, but only interdisciplinarity significantly correlated with interdisciplinary impact. Finally, an inverted U-shaped relationship was observed between multidisciplinary impact and interdisciplinary impact, suggesting that excessive multidisciplinarity may be undesirable. These results suggested that interdisciplinarity is distinct from merely the juxtaposition of multiple disciplines (multidisciplinarity). They also indicated that substantive interdisciplinary integration, rather than just encompassing diverse fields, is important for enhancing a journal’s citation impact.