Interactive highlighting for digital UML class diagrams: a new feature

Abstract

Improving the usability of software modeling tools is a quest that has led to the growth of a large set of publications covering a wide variety of usability aspects. In the case of reading and navigating within diagrams in modeling tools, existing solutions often ask designers to take time to manually manage the annotations or the layering of elements themselves to improve comfort. To free users from this manual constraint and still facilitate their work, another approach is to augment modeling tools with features capable of autonomously assisting navigation. In this paper, we focus on this approach through the proposal of an automatic highlighting feature for UML class diagrams. After describing its design, we investigate the effect of highlighting on reading and navigating within diagrams using a prototype implemented in the mxGraph environment. To measure the impact of this assistance feature, we conducted a quantitative experiment by presenting 5 types of questions on 4 types of diagrams to 54 participants. The results show that our highlighting feature significantly reduces the response time on simple direct relationship questions, but also reduces the number of errors on navigation questions. Using our highlighting feature also allows users to perceive the task significantly more positively and less demanding. However, one simple highlighting mechanism is not enough to assist complex diagram browsing questions.