Three-Level Views of the Web Service Network: An Empirical Study Based on Programmable Web

the increase of the amount of open services on the Web, combining these Web services to develop interesting and innovative applications has attracted extensive attention. Web services, service-based applications, service providers and consumers on the Internet have contributed to the emergence of the so-called "Web service ecosystem". Accurate understanding and systematic analysis of the Web service ecosystem is of paramount value. This work takes the service data collected from ProgrammableWeb.com as an empirical dataset and focuses on analyzing the Web service composition network. We propose a three-level view model for visualization of the Web service network, i.e., the Web API graph, the tag graph, and the domain graph. We firstly present the models and the constructing approaches of the graphs, and then analyze their structural characteristics. This work is not only helpful for understanding the Web service ecosystem, but also can provide support to service consumers for discovering appropriate services in developing interesting and innovative applications.