A summarization glyph for sets of unreadable visual items in treemaps
Alexandre Henrique Ichihara Pires, Rodrigo Santos do Amor Divino Lima, Carlos Gustavo Resque dos Santos, Bianchi Serique Meiguins, Anderson Gregório Marques Soares · 2020 24th International Conference Information Visualisation (IV) · 2020
The use of glyphs in data visualization aims to create a visual object that represents a data set through a set of graphic representations. Even though glyphs can help visualization techniques increase visual data representation, this approach sometimes can suffer from large amounts of data, making the glyph susceptible to perception errors of its visual variables. The grids and geomaps layouts are the most common layouts used with glyphs. However, when a more complex arrangement is considered, such as a treemap layout, the problem is even more challenging, as the small and variable areas directly influence glyph readability. Thus, this article proposes a summarization glyph to replace a set of treemap items whose areas are tiny, and that consequently would not be suitable for a glyph of their own. The proposed glyph enables data analysts to have some useful insights about the data in the overview exploration. The summarization glyph is a stacked bar chart representing the data dimensions of the tiny items. A decision tree trained on user perception tests selects the glyphs with low readability, deciding if they are kept, or included in the summarization glyph.