Evaluation of progressive treemaps to convey tree and node properties

Abstract

In this paper, we evaluate progressive treemaps (PTMs). Progressive refinement has a long tradition in image communication, but is a novel approach for information presentation. Besides technical benefits it also promises to provide advantages important for the conveyance of data properties. In this first user study in this domain, we focus on the additional value of progressive refinement for traditional treemaps to convey the topology of a given hierarchical data set and properties of its nodes. To achieve this, we compare the results gained for common squarified treemap displays with and without progression for various related tasks and set-ups. The results we obtained indicate that PTMs allow for a better conveyance of topological features and node properties in most set-ups. We also assessed the opinions of our study participants and found that PTMs also lead to a better confidence about the given answers and provide more assistance and user friendliness.