On the Truthfulness of Petal Graphs for Visualisation of Data

Abstract

A petal graph is an aesthetically attractive and applauded tool for visualising parameter sets. For instance, petal graphs are often used by Norwegian policy makers and decision makers in higher education as the Ministry of Education and Research relies on petal graphs in their reports. This study argues that petal graphs are prone to misinterpretation. It is challenging to interpret a petal graph in general, it is hard to compare two or more petal graphs and this study demonstrates that the physical characteristics of petal graphs can be incorrect in terms of the parameters on display. This study concludes that the use of petal graphs should be abolished and that other visualisation techniques to be used instead. Several alternatives are suggested.