Scientific Collaboration Index (Co-Authorship Intensity)

The Scientific Collaboration Index family quantifies how collaborative a body of research is by analyzing the number of authors per paper. In his influential 1983 review of bibliometric studies of research collaboration, K. Subramanyam consolidated the main measures: the Degree of Collaboration (the proportion of multi-authored papers), the Collaboration Index (the mean number of authors per paper), and related indicators. S. M. Lawani and later Ajiferuke and colleagues refined these into the Collaborative Coefficient, which weights papers by how many authors share them while keeping the index bounded. Together these indices give simple, comparable summaries of co-authorship intensity that have documented the long-term rise of team science across nearly every field, and they remain standard descriptive tools in scientometrics, library science, and research-policy studies of collaboration.