Do Synthesis Centers Synthesize? A Semantic Analysis of Topical Diversity in Research

Synthesis centers are a form of scientific organization that catalyzes and
supports research that integrates diverse theories, methods and data
across spatial or temporal scales to increase the generality, parsimony,
applicability, or empirical soundness of scientific explanations.
Synthesis working groups are a distinctive form of scientific
collaboration that produce consequential, high-impact publications. But no
one has asked if synthesis working groups synthesize: are their
publications substantially more diverse than others, and if so, in what
ways and with what effect? We investigate these questions by using Latent
Dirichlet Analysis to compare the topical diversity of papers published by
synthesis center collaborations with that of papers in a reference corpus.
Topical diversity was operationalized and measured in several ways, both
to reflect aggregate diversity and to emphasize particular aspects of
diversity (such as variety, evenness, and balance). Synthesis center
publications have greater topical variety and evenness, but less
disparity, than do papers in the reference corpus. The influence of
synthesis center origins on aspects of diversity is only partly mediated
by the size and heterogeneity of collaborations: when taking into account
the numbers of authors, distinct institutions, and references, synthesis
center origins retain a significant direct effect on diversity measures.
Controlling for the size and heterogeneity of collaborative groups,
synthesis center origins and diversity measures significantly influence
the visibility of publications, as indicated by citation measures. We
conclude by suggesting social processes within collaborations that might
account for the observed effects, by inviting further exploration of what
this novel textual analysis approach might reveal about interdisciplinary
research, and by offering some practical implications of our results.