Edinburgh Napier University

  This paper reports the design and comparison of three visualizations to represent the structure and content within arguments. Arguments are artefacts of reasoning widely used across domains such as education, policy making, and science. An argument is made up of sequences of statements (premises) which can support or contradict each other, individually or in groups through Boolean operators. Understanding the resulting hierarchical structure of arguments while being able to read the arguments’ text poses problems related to overview, detail, and navigation. Based on interviews with argument analysts we iteratively
designed three techniques, each using combinations of tree visualizations (sunburst, icicle), content display (in-situ, tooltip) and interactive navigation. Structured discussions with the analysts show benefits of each these techniques; e.g., sunburst being good in presenting overview but showing arguments in-situ is better than pop-ups. A controlled user study with 21 participants and three tasks shows complementary evidence suggesting that a sunburst with pop-up for the content is the best trade-off solution. Our results can inform visualizations within existing argument visualization tools and increase the visibility of ‘novel and effective’ visualizations in the argument visualization community.