Problem-solving often requires crossing boundaries, such as those between disciplines. In collaborations with third parties, however, “interdisciplinarity” is not an objective in itself, but a means for creating “synergy.” Synergy means that the whole offers more possibilities than the sum of its parts. We discuss recent advances in the operationalization and measurement of “synergy” and “interdisciplinarity”; the measurements require precision in the definitions. First, one can consider “interdisciplinarity” as composed of variety, diversity, and disparity (Stirling, 2007). The recently developed diversity indicator DIV* improves on previous operationalizations by measuring these three dimensions independently. Although policy-makers often call for “interdisciplinarity,” they may mean “synergy.” The measurement of “synergy,” however, requires a different methodology. An increase in the number of options above the sum of the options in subsets can be measured as redundancy; that is, the number of not-yet-realized options. Increasing redundancy reduces the relative uncertainty; for example, in niches. The operationalization of the two concepts as different outcome indicators enables us to distinguish analytically between the effects and the effectiveness of government or management interventions in research priorities.
 *corresponding author; Amsterdam School of Communication Research (ASCoR), University of Amsterdam, PO Box 15793, 1001 NG Amsterdam, The Netherlands; ; ORCID: 0000-0002-7835-3098.
 Institute for Statistical Studies and Economics of Knowledge, National Research University Higher School of Economics (NRU HSE), 20 Myasnitskaya St., Moscow, 101000, Russia; and School of Economics and Management, Far Eastern Federal University, 8, Sukhanova St., Vladivostok 690990, Russia; [log in to unmask] ; ORCID: 0000-0002-5441-5231.