An empirical study on the efficiency of different design pattern representations in UML class diagrams

Design patterns are recognized in the software engineering community as useful solutions to recurring design problems that improve the quality of programs. They are more and more used by developers in the design and implementation of their programs. Therefore, the visualization of the design patterns used in a program could be useful to efficiently understand how it works. Currently, a common representation to visualize design patterns is the UML collaboration notation. Previous work noticed some limitations in the UML representation and proposed new representations to tackle these limitations. However, none of these pieces of work conducted empirical studies to compare their new representations with the UML representation. We designed and conducted an empirical study to collect data on the performance of developers on basic tasks related to design pattern comprehension (i.e., identifying composition, role, participation) to evaluate the impact of three visual representations and to compare them with the UML one. We used eye-trackers to measure the developers' effort during the execution of the study. Collected data and their analyses show that stereotype-enhanced UML diagrams are more efficient for identifying composition and role than the UML collaboration notation. The UML representation and the pattern-enhanced class diagrams are more efficient for locating the classes participating in a design pattern (i.e., identifying participation).