Prefix Tag Clouds

Tag clouds are a popular way to visually represent word frequencies. However, one major limitation is that they do not relate different word forms but treat every form as an individual tag. This results not only in a non-efficient use of screen space but, in particular, leaves the viewer with no indication whether there are other forms of a word or not. To overcome this limitation, we introduce prefix tag clouds: a visualization technique that uses a prefix tree to group different word forms and visualizes the sub trees as tag cloud. The grouping is emphasized by color, while the relative frequencies of the word forms are indicated by font size. A circular tag cloud layout supports the quick identification of the most frequent words and word forms. We show the usefulness of the approach for a large dataset of paper titles from the computer science bibliography DBLP.