Are web applications more defect-prone than desktop applications?

A lot of effort in the literature has been devoted to define and validate fault taxonomies and models related to different domains, e.g. Service-oriented and Web systems, and properties, e.g. software quality and security. Nevertheless, few attempts were carried out to understand the specific nature of Web bugs and their distribution among the layers of a typical application’s architecture—presentation layer, business logic and data logic. In this paper, we present an experimental investigation aimed at studying the distribution of bugs among different layers of Web and Desktop applications. The experiment follows a well-defined procedure executed by six bachelor students. Overall, the analysis considers 1,472 bugs belonging to 20 different applications. The experimental study provides strong evidence that the presentation layer in Web applications is more defect-prone than the analogous layer in Desktop applications. An additional factor influencing the distribution of defects is represented by the application domain.