A large topic map was created to facilitate understanding of the impacts of the 2010 Gulf of Mexico Oil Spill Incident. The topic map has both a text and graphical interface, which complement each other. A formative evaluation and two summative evaluations were conducted, as qualitative studies, to assess the usefulness and usability of the large topic maps for facilitating self-regulated learning. The topic maps were found useful for knowledge fusion and discovery, and can be useful when undertaking interdisciplinary and multidisciplinary research. Users reported some usability issues about the graphical topic map, including information overload and cluttered display of topics when displaying large number of topics and their associated topics. The text topic map was found easier to use due to displaying topics, relationships and references in a linear view.
Wu, Yejun; Lehman, Amanda R.; and Dunaway, David J. (2015). "Evaluations of a Large Topic Map as a Knowledge Organization Tool for Supporting Self-Regulated Learning.." Knowledge Organization 42.6, 386-398.