How interdisciplinary is it? A new method for quantifying interdisciplinarity in student teams & examination of a large project-based program

The European Higher Education Area and the US National Academies of Science, Engineering, and Medicine have called on higher education to support interdisciplinary learning. The National Academies recommend evaluating interdisciplinary education against relevant criteria, but beyond listing student majors, institutions cannot easily quantify interdisciplinarity in education. The Rao-Stirling diversity index, which incorporates measures of cognitive distance, is used to quantify the interdisciplinarity of research. This study extends the use of the Rao-Stirling diversity index to the context of higher education to: (1) determine whether it provides a more nuanced measure of interdisciplinarity than number of majors, and (2) to examine patterns in interdisciplinarity across 79 student teams in Georgia Tech's Vertically Integrated Projects Program (N = 1218). The analysis employed cognitive distances developed in a previous study. Distributions of diversity indexes and enrollment by major were examined across the program, along with visualizations for 4 teams. Results show the Rao-Stirling diversity index provided a more comprehensive measure of team interdisciplinarity, and it indicated higher interdisciplinarity in more teams and in comparatively smaller teams than the number of majors would imply. Indexes across the program were examined graphically and explored through regression. Results indicated that higher interdisciplinarity was associated with smaller team size, implying a possible need for additional support for these teams. The utility of the index in quantifying the interdisciplinarity of teams and in revealing a previously unknown pattern confirm its usefulness within the context of higher education. Limitations, implications for research and practice, and future directions are discussed.