Evaluating visualizations: using a taxonomic guide

Although visualizations are components of many information interfaces, test ing of these visual elements is rarely undertaken except as a part of overa ll usability testing. For this reason, it is unclear what role, if any, vis ualizations actually perform. Our method involves the creation of simple vi sual prototypes and task sets based on a visual taxonomy which allows testi ng of the visualization in isolation from the rest of the system. By defini ng tests using a visual taxonomy rather than customary tasks from the appli cation domain, our method circumvents the problems of restricting evaluatio n of newer more capable systems to only those tasks which might be accompli shed with older, less capable ones. This paper will discuss methods for exh austively testing the capabilities of a visualization by mapping from a dom ain-independent taxonomy of visual tasks to a specific domain, i.e. informa tion retrieval. Experimental results are presented illustrating this approa ch to determining the role visualizations may play in supporting users in i nformation-seeking environments. Our methods could easily be extended to ot her domains including data visualization. (C) 2000 Academic Press.