Sociology

Social Sciences Citation Index

Diversity index

Mathematics

Species richness

Biology

Operationalization

Epistemology

Variety (cybernetics)

World Wide Web

Library science

Mathematical analysis

Philosophy

Paleontology

Artificial intelligence

Bibliometrics

Anthropology

Information retrieval

Data science

Index (typography)

Science Citation Index

Gini coefficient

Diversity (politics)

Citation

Computer science

Inequality

Economic inequality

Scientometrics

Journal of Informetrics

Questions of definition and measurement continue to constrain a consensus on the measurement of interdisciplinarity. Using Rao-Stirling (RS) Diversity sometimes produces anomalous results. We argue that these unexpected outcomes can be related to the use of “dual-concept diversity” which combines “variety” and “balance” in the definitions (ex ante). We propose to modify RS Diversity into a new indicator (DIV) which operationalizes “variety,” “balance,” and “disparity” independently and then combines them ex post. “Balance” can be measured using the Gini coefficient. We apply DIV to the aggregated citation patterns of 11,487 journals covered by the Journal Citation Reports 2016 of the Science Citation Index and the Social Sciences Citation Index as an empirical domain and, in more detail, to the citation patterns of 85 journals assigned to the Web-of-Science category “information science & library science” in both the cited and citing directions. We compare the results of the indicators and show that DIV provides improved results in terms of distinguishing between interdisciplinary knowledge integration (citing references) versus knowledge diffusion (cited impact). The new diversity indicator and RS diversity measure different features. A routine for the measurement of the various operationalization of diversity (in any data matrix) is made available online.

Interdisciplinarity as diversity in citation patterns among journals: Rao-Stirling diversity, relative variety, and the Gini coefficient