Guidelines on the aesthetic quality of UML class diagrams

In the past, formatting guidelines have proved to be a successful method to improve the readability of source code. With the increasing success of visual specification languages such as UML for model-driven software engineering visual guidelines are needed to standardize the presentation and the exchange of modeling diagrams with respect to human communication, understandability and readability. In this article, we introduce a new and encompassing taxonomy of visual guidelines capturing the aesthetic quality of UML class diagrams. We propose these guidelines as a framework to improve the aesthetic quality and thus the understandability of UML class diagrams. To validate this claim, we describe in detail a controlled experiment carried out as a pilot study to gather preliminary insights on the effects of some of the guideline rules on the understandability of UML class diagrams.