Abstract: This paper proposes a Web service and serviceoriented
architecture (SOA) for a computer-adaptive testing (CAT)
process on e-learning systems. The proposed architecture is
developed to solve an interoperability problem of the CAT process by
using Web service. The proposed SOA and Web service define all
services needed for the interactions between systems in order to
deliver items and essential data from Web service to the CAT Webbased
application. These services are implemented in a XML-based
architecture, platform independence and interoperability between the
Web service and CAT Web-based applications.