Comprehension of Web applications is a complex task, since several concerns co-exist in their implementation, among which the business logic, the navigation structure (as supported by hyperlinks and form submission), and persistent data storage. Design notations tailored for Web applications promise increased understandability and maintainability, thanks to the explicit representation of Web specific elements (such as hyperlinks and forms).

In this paper, we report the results obtained from the execution of an empirical study involving comprehension tasks on two Web applications. Assuming the availability of the source code, two forms of design diagrams have been recovered from the code: standard UML diagrams and UML diagrams extended with Conallen?s stereotypes. The research question addressed by this study is whether enriching standard UML diagrams with Web specific stereotypes gives any significant contribution to the understandability of the Web applications.